Methods, systems and devices for carpal tunnel release

ABSTRACT

Described herein are methods, systems and devices for cutting a ligament of a patient. In some embodiments, the method may include the steps of advancing a cannulated probe into a patient, advancing the distal end of the tissue modification device assembly posteriorly through the skin of the patient such that it exits the patient, exposing at least one tissue modification element of the tissue modification device assembly, and reciprocating at least a portion of the tissue modification device assembly by alternately pulling on proximal and distal portions of the tissue modification device assembly to draw the at least one tissue modification element across the ligament to cut the ligament, in some embodiments, the system may include a probe, a tissue modification device, and a sheath. The tissue modification device may include a proximal handle, at least one tissue modification element configured cut ligament, and a sharp distal tip.

CROSS-REFERENCES TO RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 11/251,199, titled “DEVICES AND METHODS FOR TISSUEMODIFICATION”, filed Oct. 15, 2005, which claims the benefit of U.S.Provisional Patent Application Nos. 60/619,306, filed Oct. 15, 2004;60/622,865, filed Oct. 28, 2004; 60/681,719, filed May 16, 2005;60/681,864, filed May 16, 2005; and 60/685,190, filed May 27, 2005, eachof these applications is herein incorporated by reference in itsentirety.

This patent application is also a continuation-in-part of U.S. patentapplication Ser. No. 11/429,377, titled “FLEXIBLE TISSUE RASP”, filedMay 4, 2006, which is a continuation-in-part of PCT Patent ApplicationNo. PCT/US2005/037136, filed Oct. 15, 2005, which claims the benefit ofU.S. Provisional Application Nos. 60/619,306, filed Oct. 15, 2004;60/622,865, filed Oct. 28, 2004; 60/681,719, filed May 16, 2005;60/681,864, filed May 16, 2005; and 60/685,190, filed May 27, 2005, eachof these applications is herein incorporated by reference in itsentirety. U.S. patent application Ser. No. 11/429,377 is also acontinuation-in-part of U.S. patent application Ser. No. 11/375,265,entitled “METHODS AND APPARATUS FOR TISSUE MODIFICATION”, filed Mar. 13,2006, now U.S. Pat. No. 7,887,538, which is a continuation-in-part ofPCT Patent Application No. PCT/US2005/037136, filed Oct. 15, 2005, whichclaims the benefit of U.S. Provisional Application Nos. 60/619,306,filed Oct. 15, 2004; 60/622,865, filed Oct. 28, 2004; 60/681,719, filedMay 16, 2005; 60/681,864, filed May 16, 2005; and 60/685,190, filed May27, 2005, each of these applications is herein incorporated by referencein its entirety.

This patent application is also a continuation-in-part of U.S. patentapplication Ser. No. 11/687,548, titled “TISSUE REMOVAL WITH AT LEASTPARTIALLY FLEXIBLE DEVICES”, filed Mar. 16, 2007, which is acontinuation-in-part of U.S. patent application Ser. No. 11/429,377,filed May 4, 2006, and also claims the benefit of 60/869,070, filed Dec.7, 2006, each of these applications is herein incorporated by referencein its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety to the sameextent as if each individual publication or patent application wasspecifically and individually indicated to be incorporated by reference.

FIELD OF THE INVENTION

Described herein are systems, devices, and methods for performingsurgical procedures. In particular, described herein are systems,devices and methods for carpal tunnel release procedures.

BACKGROUND OF THE INVENTION

The present invention relates generally to medical/surgical devices andmethods. More specifically, the present invention relates to flexibletissue modification devices and methods.

A significant number of surgical procedures involve modifying tissue ina patient's body, such as by removing, cutting, shaving, abrading,shrinking, ablating or otherwise modifying tissue. Minimally invasive(or “less invasive”) surgical procedures often involve modifying tissuethrough one or more small incisions or percutaneous access, and thus maybe more technically challenging procedures. Some of the challenges ofminimally invasive tissue modification procedures include working in asmaller operating field, working with smaller devices, and trying tooperate with reduced or even no direct visualization of the tissue (ortissues) being modified. For example, using arthroscopic surgicaltechniques for repairing joints such as the knee or the shoulder, it maybe quite challenging to modify certain tissues to achieve a desiredresult, due to the required small size of arthroscopic instruments, theconfined surgical space of the joint, lack of direct visualization ofthe surgical space, and the like. It may be particularly challenging insome surgical procedures, for example, to cut or contour bone orligamentous tissue with currently available minimally invasive tools andtechniques. For example, trying to shave a thin slice of bone off acurved bony surface, using a small-diameter tool in a confined spacewith little or no ability to see the surface being cut, as may berequired in some procedures, may be incredibly challenging or evenimpossible using currently available devices.

One area of surgery which would likely benefit from the development ofless invasive techniques is the treatment of spinal stenosis. Spinalstenosis occurs when nerve tissue and/or the blood vessels supplyingnerve tissue in the spine become impinged by one or more structurespressing against them, causing symptoms. The most common form of spinalstenosis occurs in the lower (or lumbar) spine and can cause severepain, numbness and/or loss of function in the lower back and/or one orboth lower limb.

FIG. 1 is a top view of a vertebra with the cauda equina (the bundle ofnerves that extends from the base of the spinal cord) shown in crosssection and two nerve roots branching from the cauda equina to exit thecentral spinal canal and extend through intervertebral foramina oneither side of the vertebra. Spinal stenosis can occur when the spinalcord, cauda equina and/or nerve root(s) are impinged by one or moretissues in the spine, such as buckled or thickened ligamentum flavum,hypertrophied facet joint (shown as superior articular processes in FIG.1), osteophytes (or “bone spurs”) on vertebrae, spondylolisthesis(sliding of one vertebra relative to an adjacent vertebra), facet jointsynovial cysts, and/or collapse, bulging or herniation of anintervertebral disc. Impingement of neural and/or neurovascular tissuein the spine by one or more of these tissues may cause pain, numbnessand/or loss of strength or mobility in one or both of a patient's lowerlimbs and/or of the patient's back.

In the United States, spinal stenosis occurs with an incidence ofbetween 4% and 6% (or more) of adults aged 50 and older and is the mostfrequent reason cited for back surgery in patients aged 60 and older.Patients suffering from spinal stenosis are typically first treated withconservative approaches such as exercise therapy, analgesics,anti-inflammatory medications, and epidural steroid injections. Whenthese conservative treatment options fail and symptoms are severe, as isfrequently the case, surgery may be required to remove impinging tissueand decompress the impinged nerve tissue.

Lumbar spinal stenosis surgery involves first making an incision in theback and stripping muscles and supporting structures away from the spineto expose the posterior aspect of the vertebral column. Thickenedligamentum flavum is then exposed by complete or partial removal of thebony arch (lamina) covering the back of the spinal canal (laminectomy orlaminotomy). In addition, the surgery often includes partial or completefacetectomy (removal of all or part of one or more facet joints), toremove impinging ligamentum flavum or bone tissue. Spinal stenosissurgery is performed under general anesthesia, and patients are usuallyadmitted to the hospital for five to seven days after surgery, with fullrecovery from surgery requiring between six weeks and three months. Manypatients need extended therapy at a rehabilitation facility to regainenough mobility to live independently.

Removal of vertebral bone, as occurs in laminectomy and facetectomy,often leaves the effected area of the spine very unstable, leading to aneed for an additional highly invasive fusion procedure that puts extrademands on the patient's vertebrae and limits the patient's ability tomove. Unfortunately, a surgical spine fusion results in a loss ofability to move the fused section of the back, diminishing the patient'srange of motion and causing stress on the discs and facet joints ofadjacent vertebral segments. Such stress on adjacent vertebrae oftenleads to further dysfunction of the spine, back pain, lower leg weaknessor pain, and/or other symptoms. Furthermore, using current surgicaltechniques, gaining sufficient access to the spine to perform alaminectomy, facetectomy and spinal fusion requires dissecting through awide incision on the back and typically causes extensive muscle damage,leading to significant post-operative pain and lengthy rehabilitation.Thus, while laminectomy, facetectomy, and spinal fusion frequentlyimprove symptoms of neural and neurovascular impingement in the shortterm, these procedures are highly invasive, diminish spinal function,drastically disrupt normal anatomy, and increase long-term morbidityabove levels seen in untreated patients.

Therefore, it would be desirable to have less invasive methods anddevices for modifying target tissue in a spine to help ameliorate ortreat spinal stenosis, while inhibiting unwanted damage to non-targettissues. Ideally, such techniques and devices would reduce neural and/orneurovascular impingement without removing significant amounts ofvertebral bone, joint, or other spinal support structures, therebyavoiding the need for spinal fusion and, ideally, reducing the long-termmorbidity resulting from currently available surgical treatments. It mayalso be advantageous to have minimally invasive or less invasive tissuemodification devices capable of treating target tissues in parts of thebody other than the spine. At least some of these objectives will be metby the present invention.

SUMMARY OF THE INVENTION

In various embodiments, devices, systems and methods of the presentinvention provide for minimally invasive or less invasive modificationof tissue in a patient. For the purposes of this application, the phrase“tissue modification” includes any type of tissue modification, such asbut not limited to removing, cutting, shaving, abrading, shrinking,ablating, shredding, sanding, filing, contouring, carving, melting,heating, cooling, desiccating, expanding, moving, delivering medicationor other substance(s) to tissue and/or delivering an implantable device,such as a stent, to tissue to modify the tissue's configuration, shape,position or the like.

In one aspect of the present invention, a device for modifying tissue ina patient may include: an elongate body having a rigid proximal portionand a flexible distal portion having first and second major surfaces; aproximal handle coupled with the proximal portion of the body; one ormore tissue modifying members disposed along the first major surface ofthe distal portion of the body; a guidewire coupled with and extendingfrom the distal portion of the body; and a distal handle removablycouplable with the guidewire outside the patient. In some embodiments,the device may be configured to modify spinal tissue, and the device maybe configured to extend into the patient's body, along a curved paththrough an intervertebral foramen of the spine, and out of the patient'sbody, such that at least part of the flexible distal portion of theelongate body of the device extends into the intervertebral foramen, andthe proximal and distal handles reside outside the patient. In oneembodiment, a height of the tissue modifying member(s) may be greaterthan a thickness of a ligamentum flavum of the spine. In alternativeembodiments, the device may be configured for use in modifying any of anumber of other tissues in the spine or in other parts of a patient'sbody. In one embodiment, for example, a device may be used to incise thetransverse carpal ligament while inhibiting damage of the median nerveto perform a minimally invasive carpal tunnel release procedure. Othertissues in the knee, shoulder, elbow, foot, ankle or other parts of thebody may be addressed in alternative embodiments. For example, a devicemay be used to release of the lacinate ligament of the tarsal tunnel ofthe foot and/or decompress the posterior tibial nerve, while inhibitingdamage of the tibial nerve or its associated branches to perform aminimally invasive tarsal tunnel release procedure.

In various alternative embodiments, the tissue modifying member(s) of atissue modification device may include, but are not limited to, one ormore uni-directional blades, bi-directional blades, teeth, hooks, barbs,hooks, pieces of Gigli saw (or other wire saw), wires, meshes, wovenmaterial, knitted material, braided material, planes, graters, raisedbumps, other abrasive surfaces, other abrasive materials and/ordeliverable substances adhered to or formed in the first major surface.Some embodiments may include one type of tissue modifying member, whileother embodiments may include a combination of different tissuemodifying members. In some embodiments, the tissue modifying member(s)may be fixedly attached to or formed in the first major surface, and thedevice may operate by reciprocating the entire device (or most of it)back and forth to cause the tissue modifying member(s) to modify tissue.In alternative embodiments, the tissue modifying member(s) may bemoveably attached to or formed in the first major surface, and thedevice may further include an actuator coupled with the tissue modifyingmember(s) and extending to the proximal handle for actuating the tissuemodifying member(s).

In one embodiment, the elongate body may be at least partially hollow,the distal portion may be flatter than the proximal portion, and thetissue modifying members may comprise blades formed in the first majorsurface of the distal portion. In some embodiments, the guidewire may beremovably coupled with the distal portion of the elongate body via, aguidewire coupler comprising a cavity for containing a shaped tip of theguidewire, and wherein the guidewire comprises at least one shaped tipfor fitting within the cavity.

Some embodiments may further include a material disposed over a portionof the elongate body distal portion to provide the distal portion withsmooth edges. For example, such a material may comprise, in someembodiments, a polymeric cover disposed over the distal portion with oneor more openings through which the tissue modifying member(s) protrude.In one embodiment, the material may be further configured to collecttissue removed by the tissue modifying member(s). In some embodiments,the device may include a tissue collection chamber formed in or attachedto the elongate body.

In another aspect of the present invention, a device for modifyingtissue in a patient may include an elongate body, a proximal handlecoupled with the proximal portion of the body, one or more tissuemodifying members disposed along the first major surface of theintermediate portion of the body, and a distal handle removablycouplable with the distal portion of the body outside the patient. Insome embodiments, the elongate body may include a rigid proximalportion, a flexible distal portion, and an intermediate flexible portiondisposed between the proximal and distal portions and having first andsecond major surfaces. In some embodiments, the device may be configuredto modify spinal tissue, and the device may be configured to extend intothe patient's body, along a curved path through an intervertebralforamen of the spine, and out of the patient's body, such that at leastpart of the flexible intermediate portion of the elongate body of thedevice extends into the intervertebral foramen, and the proximal anddistal handles reside outside the patient.

In some embodiments, the distal portion of the elongate body maycomprise a guidewire coupled with the intermediate portion of the body.In some embodiments, at least the proximal and intermediate portions ofthe elongate body are at least partially hollow, thus forming at leastone lumen. For example, in some embodiments, the at least one lumen mayinclude a suction lumen and/or an irrigation lumen. Optionally, someembodiments may include at least one tissue transport member slidablydisposed within the lumen and configured to remove tissue out of thedevice. For example, in one embodiment the tissue transport member maycomprise one or more flexible wires having tissue collection portionsdisposed under the tissue modifying member(s) of the device. Such tissuecollection portions may include, for example, shaped portions of thewire(s), adhesive coating(s) on the wire(s), tissue collectingmaterials) on the wire(s), adhesive materials) used to make the wire(s)themselves and/or the like. In alternative embodiments, the tissuetransport member may comprise a piece of tissue adhering materialdisposed under the tissue modifying member(s) of the device. In otheralternative embodiments, the tissue transport member may comprise aremovable tissue collection chamber disposed under the tissue modifyingmember(s) of the device. Alternatively, the tissue transport member maycomprise at least one uni-directional valve for allowing tissue to passthrough the shaft toward the proximal handle while preventing the cuttissue from passing through the valve(s) toward the tissue modifyingmember(s) of the device.

In some embodiments, at least part of the elongate body may besufficiently flexible to be compressible, such that tissue may be movedthrough the elongate body by compressing the compressible portion. Someembodiments of the device may further include a tissue collectionchamber formed in or attached to the elongate body.

In another aspect of the present invention, a kit for modifying tissuein a patient may include a tissue modification device, a guidewireconfigured to couple with a guidewire coupler of the device, and adistal handle removably couplable with the guidewire outside thepatient. The tissue modification device may include a rigid shaft havinga proximal end and a distal end, a flexible substrate extending from thedistal end of the shaft, a proximal handle coupled with the shaft at ornear its proximal end, one or more tissue modifying members disposedalong one side of the substrate, and a guidewire coupler disposed on thesubstrate, in some embodiments, the tissue modification device andguidewire, coupled together, may be configured to extend into thepatient's body, along a curved path through an intervertebral foramen ofthe spine, and out of the patient's body, such that at least part of theflexible substrate extends into the intervertebral foramen, and theproximal and distal handles reside outside the patient.

Optionally, some embodiments may also include at least one probe forpassing the guidewire between target and non-target tissues in apatient. For example, in some embodiments, the probe may comprise aneedle. In alternative embodiments, the probe may comprise a curved,cannulated probe. In any case, a probe may optionally include a flexibleguide member for passing through the probe, and such a guide member mayhave an inner diameter selected to allow passage of the guidewiretherethrough.

In some embodiments, the tissue modification device may further includea tissue collection member coupled with the substrate and configured tocollect tissue. Such an embodiment may optionally further include tissuetransport means configured to transport the collected tissue through thedevice.

In another aspect of the present invention, a method for modifyingtarget tissue in a patient while inhibiting damage to non-target tissuesmay involve: advancing a flexible distal portion of an elongate tissuemodification device into the patient's body and along a curved pathbetween target and non-target tissues, such that a distal end of thedistal portion exits the patient's body; coupling a first handle withthe distal portion outside the patient; applying a first tensioningforce to the first handle; applying a second tensioning force to asecond handle coupled with a rigid proximal portion of the device, thefirst and second tensioning forces urging one or more tissue modifyingmembers disposed along the flexible distal portion against the targettissue; and reciprocating at least a portion of the device back andforth, while maintaining at least some of the tensioning force, to causethe tissue modifying member(s) to modify the target tissue.

In some embodiments, advancing the distal portion may involve advancingthrough an intervertebral foramen of the patient's spine, andreciprocating the device may involve modifying ligamentum flavum and/orbone. In some embodiments, advancing the distal portion may involveadvancing percutaneously into the patient. In some embodiments, thedistal portion of the device may be advanced into the patient's spinewithout removing bone, and only ligamentum flavum tissue may bemodified. The method may optionally further involve manipulating thesecond handle and thus the rigid proximal portion to steer the flexibleportion of the device.

In one embodiment, the flexible distal portion may include a flexiblesubstrate coupled with a flexible guidewire, coupling the first handlemay involve coupling with the guidewire, and advancing the distalportion may involve pulling the guidewire with the first handle toadvance the flexible substrate between the target and non-target tissue.In various embodiment, the target tissue may include, but is not limitedto, ligament, tendon, bone, tumor, cyst, cartilage, scar, osteophyte andinflammatory tissue, and the non-target tissue may include, but is notlimited to, neural tissue and neurovascular tissue. In one embodiment,for example, the target tissue may include a transverse carpal ligament,and the non-target tissue may include a median nerve. Alternatively, forexample, a device may be used to release of the lacinate ligament of thetarsal tunnel of the foot and/or decompress the posterior tibial nerve,while inhibiting damage of the tibial nerve or its associated branchesto perform a minimally invasive tarsal tunnel release procedure.

In some embodiments, the tensioning forces may urge a plurality oftissue modifying members against a curved target tissue along a lengthof the flexible portion. In some embodiments, reciprocating at least aportion of the device may involve reciprocating an entire portionbetween the first and second handles, and reciprocating may cause atissue modifying surface of the flexible portion to modify the targettissue while an atraumatic surface of the flexible portion faces thenon-target tissue. In alternative embodiments, reciprocating at least aportion of the device may involve reciprocating a tissue moth surface ofthe flexible portion, and reciprocating may cause the tissue modifyingsurface to modify the target tissue while an atraumatic surface of theflexible portion faces the non-target tissue.

Optionally, in some embodiments, the method may further involvecollecting cut tissue in the tissue modification device. In someembodiments, the method may additionally include transporting the cuttissue out of the patient through the tissue modification device. Forexample, transporting the cut tissue may involve applying suction and/orirrigation in the tissue collection chamber. Alternatively, transportingthe cut tissue may involve collecting the cut tissue on or in one ormore tissue transport members and withdrawing the tissue transportmember(s) through the tissue modification device.

In another aspect, the invention provides a method for removing a targetligament and/or bone tissue of a patient. The method comprises providingan elongate body having an axis and an elongate, axially flexibleportion affixed to a rigid shaft portion. The flexible portion ispositioned within the patient so that a first surface of the flexibleportion is oriented toward the target tissue. The first surface isshifted toward a target region of the target tissue by moving the rigidportion, and the target region of the target tissue is removed with atissue modifying member disposed along the first surface.

Optionally the rigid portion extends axially from a first end of theflexible portion. The flexible portion can be flexible in one lateralorientation, and may be stiffer in another lateral orientation (forexample, in the direction in which it is shifted). The flexible portioncan be positioned so that the first surface of the flexible portionbends over the target tissue, and/or the flexible portion may be axiallytensioned to urge the first surface toward the target tissue. Thetension can be applied to the first end by pulling the rigid portionfrom outside the patient.

In many embodiments, the surface will be shifted by applying torque tothe rigid portion from outside the body portion. The rigid portion canthen rotate the flexible portion about the axis an as to shift anorientation of the first surface toward a target region of the targettissue. Where the target tissue has a convex surface defining an outwardorientation and an inward orientation, and where the first surface isbordered by first and second opposed edges, the target tissue adjacentthe first edge may be inward of the target tissue adjacent the secondedge. As a result, the tension of the flexible portion may inducerolling of the flexible portion about the axis toward the first edge.The torquing of the shaft portion may counteract the tension-inducedrolling to inhibit flipping of the flexible portion.

A distal handle may be coupled with a second end of the flexibleportion, and the flexible portion may be manually tensioned bysimultaneous pulling, from outside the patient, on the first and secondhandles. Axially moving the tissue modifying member along a curving pathmay be performed within the patient by relative movement between thefirst and second handles, the curving path including the bend over thetarget tissue. Lateral translation of the rigid portion from outside thepatient can be used to induce the lateral shifting of the first surface,particularly where the flexible portion is stiffer in a second lateralorientation extending along the first surface, with the first surfacetypically shifting along that second lateral orientation.

In some embodiments, pivoting of the rigid portion about tissuesdisposed along the rigid portion may be used to induce the lateralshifting of the first surface. Optionally, a first handle may beattached to the rigid portion outside the patient, and the flexibleportion can be manually tensioned and shifted by manipulating the firsthandle with a hand. A distal handle can be coupled with a second end ofthe flexible portion, and the flexible portion can be manually tensionedby simultaneous pulling, from outside the patient, on the first andsecond handles. Axially moving of the tissue modifying member along acurving path within the patient can be effected by relative movementbetween the first and second handles, typically with the curving pathincluding a bend over the target tissue. Reciprocation of the tissuemodifying member along the curved path and against the target tissue canbe provided by sequentially pulling on the first and second handles sothat a cutting edge of the tissue modifying member incises the targettissue. In some embodiments, another rigid portion extends from thesecond handle to the second end of the flexible portion inside thepatient, with the first surface of the flexible portion being shiftedusing both rigid portions.

In yet another aspect, the invention provides a system for removing atarget tissue of a patient. The system comprises an elongate flexibleportion having a first end and a second end with an axis therebetween.The flexible portion has a first surface extending along the axis and isaxially bendable in a first lateral orientation. A rigid portion isextendable from the flexible body portion so that pulling on the rigidportion can axially tension the flexible portion to urge the firstsurface toward the target tissue. Movement of the rigid portion can beused to shift the first surface toward a target region of the targettissue. A tissue modifying member disposed along the first surface canbe configured to effect removal of the target region of the targettissue.

Also described herein are methods of cutting a ligament of a patient. Ingeneral, the method may include the steps of advancing a cannulatedprobe into a patient, advancing a tissue modification device assemblythrough the cannulated probe and anterior to a ligament of a patient,advancing the distal end of the tissue modification device assemblyposteriorly through the skin of the patient such that it exits thepatient, exposing at least one tissue modification element of the tissuemodification device assembly, and reciprocating at least a portion ofthe tissue modification device assembly by alternately pulling onproximal and distal portions of the tissue modification device assemblyto draw the at least one tissue modification element across the ligamentto cut the ligament.

In some embodiments, the method may further include the step ofconfirming proper placement with a nerve stimulator. In someembodiments, the method may further include the step of attaching anerve stimulator to a tissue modification device assembly.

In some embodiments, the method may further include the step of couplinga distal handle to the distal end of the tissue modification deviceassembly, exterior to the patient.

Alternatively, in some embodiments, the method of cutting a ligament ofa patient may include the steps of advancing a tissue modificationdevice assembly into a patient and anterior to a ligament of a patient,advancing the distal end of the tissue modification device assemblyposteriorly through the skin of the patient such that it exits thepatient, exposing at least one tissue modification element of the tissuemodification device assembly, and reciprocating at least a portion ofthe tissue modification device assembly by alternately pulling onproximal and distal portions of the tissue modification device assemblyto draw the at least one tissue modification element across the ligamentto cut the ligament.

In some embodiments, the method may further include the step ofconfirming proper placement with a nerve stimulator. In someembodiments, the method may further include the step of attaching anerve stimulator to a tissue modification device assembly.

In some embodiments, the method may further include the step of couplinga distal handle to the distal end of the tissue modification deviceassembly, exterior to the patient.

Also described herein are systems for cutting a ligament of a patient.In general, the systems may include a probe configured to be advancedinto a patient and a tissue modification device. The tissue modificationdevice may include a proximal handle, at least one tissue modificationelement configured cut ligament, and a sharp distal tip, wherein thesharp distal tip is configured to be advanced anterior to a ligament ofa patient and posteriorly through the skin of the patient such that itexits the patient. In some embodiments, the system may further include asheath configured to limit the exposure of the tissue modificationelement of tissue modification device, wherein the tissue modificationdevice is configured for placement within the sheath such that tissuemodification element is locally exposed by the sheath.

In some embodiments, the system may further include a nerve stimulatorconfigured to couple to the tissue modification device to confirmcorrect placement of the tissue modification device. In someembodiments, the system may further include a distal handle configuredto couple to the sharp distal tip of the tissue modification device.

In some embodiments, the probe is a cannulated probe and the tissuemodification device is configured to be deployed through the cannulatedprobe.

Also described herein are devices for cutting ligament of a patient. Ingeneral, the device may include a proximal handle, at least one tissuemodification element configured cut ligament, a sharp distal tip,wherein the sharp distal tip is configured to be advanced anterior to aligament of a patient and posteriorly through the skin of the patientsuch that it exits the patient, and a sheath configured to limit theexposure of the tissue modification element, wherein the tissuemodification element is configured for placement within the sheath suchthat tissue modification element is locally exposed by the sheath.

In some embodiments, the device may further include a distal handleconfigured to couple to the sharp distal tip.

Also described herein are systems for cutting a ligament of a patient.In general, the systems may include a probe configured to be advancedinto a patient and a tissue modification device. The tissue modificationdevice may include a proximal handle, an abrasive surface configured cutligament, a sharp distal tip, wherein the sharp distal tip is configuredto be advanced anterior to a ligament of a patient and posteriorlythrough the skin of the patient such that it exits the patient. Thesystems may also include a protective cover disposed about the tissuemodification device configured to limit the exposure of the abrasivesurface.

In some embodiments, the system may further include a nerve stimulatorconfigured to couple to the tissue modification device to confirmcorrect placement of the tissue modification device.

In some embodiments, the system may further include a distal handleconfigured to couple to the sharp distal tip of the tissue modificationdevice.

In some embodiments, the probe is a cannulated probe and the tissuemodification device is configured to be deployed through the cannulatedprobe.

Also described herein are methods of performing a minimally invasivecarpal tunnel release procedure to cut a target transverse carpalligament. In general, the methods may include the steps of advancing aprobe percutaneously though a patient's skin from a first location,advancing a tissue modification device from the first location andbetween the target ligament and non-target tissue so that a proximalhandle on the tissue modification device extends from the patient at thefirst location, wherein the tissue modification device includes aflexible distal region having uni-directional blades, attaching a distalhandle in communication with the distal end of the tissue modificationdevice, wherein the distal handle extends from the patient at a secondlocation, and reciprocating the tissue modification device using theproximal handle and distal handles to incise the transverse carpalligament with the uni-directional blades.

In some embodiments, the tissue modification device includes anatraumatic cover forming an aperture through which the blades may engagethe target ligament.

In some embodiments, reciprocating further includes tensioning thetissue modification device to urge the blades towards the targetligament.

In some embodiments, the methods further include the step of verifyingcorrect device placement with a nerve stimulator. In some embodiments,the methods further include the step of attaching a nerve stimulator toa tissue modification device assembly.

Also described herein are methods of performing a minimally invasivecarpal tunnel release procedure to cut a target transverse carpalligament. In general the methods may include the steps of advancing atissue modification device through a small incision at a first locationon a subject's skin and between the target ligament and non-targettissue so that a proximal handle on the tissue modification deviceextends from the patient at the first location, wherein the tissuemodification device includes a flexible distal region havinguni-directional blades, attaching a distal handle in communication withthe distal end of the tissue modification device, wherein the distalhandle extends from the patient at a second location, and reciprocatingthe tissue modification device using the proximal handle and distalhandles to incise the transverse carpal ligament with theuni-directional blades.

In some embodiments, the tissue modification device comprises anatraumatic cover forming an aperture through which the blades may engagethe target ligament.

In some embodiments, reciprocating further comprises tensioning thetissue modification device to urge the blades towards the targetligament.

In some embodiments, the methods further include verifying correctdevice placement with a nerve stimulator. In some embodiments, themethods further include attaching a nerve stimulator to a tissuemodification device assembly.

Also described herein are systems for performing a minimally invasivecarpal tunnel release procedure to cut a target transverse carpalligament. In general the systems may include a probe configured to beadvanced percutaneously though a patient's skin from a first location, atissue modification device comprising a proximal handle and a flexibledistal region having uni-directional blades, and a distal handleconfigured to connect to the distal end of the tissue modificationdevice, wherein the tissue modification device is configured to bereciprocated using the proximal handle and distal handles to incise thetransverse carpal ligament with the uni-directional blades.

In some embodiments, the system may further include a nerve stimulatorconfigured to couple to the tissue modification device and verifycorrect placement of the tissue modification device.

In some embodiments, the probe is a cannulated probe and the tissuemodification device assembly is configured to be deployed through thecannulated probe.

Also described herein are devices for performing a minimally invasivecarpal tunnel release procedure to cut a target transverse carpalligament. In general the device may include a tissue modification devicecomprising a proximal handle and a flexible distal region havinguni-directional blades, a distal handle configured to connect to thedistal end of the tissue modification device, wherein the tissuemodification device is configured to be reciprocated using the proximalhandle and distal handles to incise the transverse carpal ligament withthe uni-directional blades.

Also described herein are methods for modifying a transverse carpalligament in a patient. In general the methods may include the steps ofadvancing a distal portion of an elongate tissue modification deviceinto the patient's body and along a path between target and non-targettissues, such that a distal end of the distal portion exits thepatient's body, applying a first force to a distal portion of the tissuemodification device outside the patient, applying a second force to aproximal portion of the tissue modification device, the first and secondforces urging one or more tissue modifying members of the tissuemodification device against the target tissue, reciprocating at least aportion of the tissue modification device back and forth to cause theone or more tissue modifying members to modify the target tissue.

In some embodiments, the target tissue is the transverse carpalligament.

In some embodiments, reciprocating at least a portion of the tissuemodification device back and forth causes the one or more tissuemodifying members incise the transverse carpal ligament.

In some embodiments, the method may further include coupling a firsthandle with the distal portion of the tissue modification device outsidethe patient and applying the first force to the distal handle.

These and other aspects and embodiments are described more fully belowin the Detailed Description, with reference to the attached Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a vertebra with the cauda equina shown in crosssection and two nerve roots branching from the cauda equina to exit thecentral spinal canal and extend through intervertebral foramina oneither side of the vertebra;

FIG. 2A is a cross-sectional view of a patient's back and a side view ofa flexible tissue modification device in position in a spine, accordingto one embodiment of the present invention;

FIG. 2B is a diagrammatic view of a generic portion of a patient's body,showing target and non-target tissue, with the device of FIG. 2A inposition to modify target tissue, according to one embodiment of thepresent invention;

FIG. 2C is a side view of a tissue modification device, according to analternative embodiment of the present invention;

FIG. 2D is a side view of a tissue modification device, according toanother alternative embodiment of the present invention;

FIG. 3A is a view of a kit or system for modifying tissue, according toone embodiment of the present invention;

FIG. 3B is a side view of a portion of the kit of FIG. 3B;

FIGS. 4A-4E demonstrate a method for inserting and using a flexibletissue modification device to modify tissue while inhibiting damage tonon-target tissue, according to one embodiment of the present invention;

FIG. 5A is a perspective view of a flexible portion of a tissuemodification device, according to one embodiment of the presentinvention;

FIGS. 5B and 5C are end-on and side views of blade and substrateportions of the portion of the device of FIG. 5A;

FIG. 6 is a perspective view of a portion of a flexible substrate and awire saw tissue modifying member of a tissue modification device,according to one embodiment of the present invention;

FIG. 7 is a perspective view of a portion of a flexible substrate andmultiple wire saw tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 8 is a perspective view of a portion of a flexible substrate and anabrasive surface tissue modifying member of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 9 is a perspective view of a portion of a flexible substrate andmultiple tooth-like tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 10 is a perspective view of a portion of a flexible substrate and atwo-blade tissue modifying member of a tissue modification device,according to an alternative embodiment of the present invention;

FIG. 11 is a perspective view of a portion of a flexible substrate andmultiple shark-tooth-shaped tissue modifying members of a tissuemodification device, according to an alternative embodiment of thepresent invention;

FIG. 12 is a perspective view of a portion of a flexible substrate andmultiple cheese-grater-shaped tissue modifying members of a tissuemodification device, according to an alternative embodiment of thepresent invention;

FIG. 13 is a perspective view of a portion of a flexible substrate andmultiple raised tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 14 is a perspective view of a portion of a flexible substrate andmultiple raised-flap tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 15 is a perspective view of a portion of a flexible substrate andmultiple rounded tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 16 is a perspective view of a portion of a flexible substrate andmultiple raised-flap tissue modifying members of a tissue modificationdevice, according to an alternative embodiment of the present invention;

FIG. 17 is a perspective view of a portion of a flexible substrate andmultiple, differently shaped tissue modifying members of a tissuemodification device, according to an alternative embodiment of thepresent invention;

FIG. 18 is a perspective view of a portion of a flexible substrate andbarbed-hook and raised-flap tissue modifying members of a tissuemodification device, according to an alternative embodiment of thepresent invention;

FIG. 19 is a perspective view of a portion of a wire mesh flexibletissue modification device, according to an alternative embodiment ofthe present invention;

FIG. 20 is a perspective view of a portion of a flattened, hollow,flexible tissue modification device, according to an alternativeembodiment of the present invention;

FIG. 21 is a perspective view of a portion of a flexible substrate andcheese-grater-shaped tissue modifying members coupled with a tissuecapture member of a tissue modification device, according to analternative embodiment of the present invention;

FIG. 22 is a perspective view of a portion of a moveable-link flexibletissue modification device, according to an alternative embodiment ofthe present invention;

FIG. 23 is a side view of a tissue modification device in a position forperforming a tissue modification procedure, showing a generic bone, softtissue and non-target tissue, according to one embodiment of the presentinvention;

FIG. 24 is a side view of a tissue modification device with verticallyoriented blades, according to one embodiment of the present invention;

FIG. 25 is a perspective view of a flexible portion of a tissuemodification device with vertically oriented blades, according to oneembodiment of the present invention;

FIGS. 26A and 26B illustrate how tension in a flexible portion of atissue modification device bent over a target tissue can urge blades orother tissue modification devices into the target tissue, and how torqueto the rigid portion of the tissue modification device can maintain oralter an orientation of the flexible member and inhibit flipping of theflexible member;

FIG. 27A is a perspective view schematically illustrating shifting ofthe flexible member laterally along a target tissue by laterallytranslating the proximal rigid portion, and/or by pivoting the rigidportion about tissues along the site of insertion;

FIG. 27B schematically illustrates lateral translation and pivoting ofthe rigid portion to effect shifting of the flexible portion relative tothe target tissue, and also schematically illustrates an optional rigidtubular shaft coupled to a distal handle to similarly allow shifting ofthe distal end of the flexible portion and provide enhanced control overtarget tissue remodeling and/or removal;

FIGS. 28A-28E are end-on views of a flexible portion of a tissuemodification device with vertically oriented blades, demonstrating amethod for shifting the device back and forth laterally in anintervertebral foramen, according to one embodiment of the presentinvention;

FIG. 29 is a perspective view of a double-blade member of the tissuemodification device portion of FIG. 31 for attachment to a flexibleportion of a tissue modification device, according to one embodiment ofthe present invention;

FIG. 30 is a perspective view of a double-blade member of the tissuemodification device portion of FIG. 32 for attachment to a flexibleportion of a tissue modification device, according to an alternativeembodiment of the present invention;

FIG. 33A is a schematic view of apparatus of the present invention forobtaining open surgical access;

FIGS. 33B-33E are cross-sectional views through a patient's spine,illustrating open surgical methods of using the apparatus of FIG. 33A toobtain access;

FIGS. 34A and 34B are cross-sectional views through a patient's spine,illustrating a variation of the methods and apparatus of FIG. 33;

FIGS. 35-42 are cross-sectional views through a patient's spine,illustrating a method and apparatus for selective surgical removal oftissue;

FIGS. 43-48 are partial cross-sectional views through a patient's spine,illustrating a double barrel system used with additional methods andapparatus for placement of an abrasion apparatus through the neuralforamina for selective surgical removal of tissue;

FIGS. 49-61 are cross-sectional views through a patient's spine,illustrating a variation of the methods and apparatus of FIGS. 43-48;

FIG. 62 is a cross-sectional view through a patients spine, illustratinga methods and apparatus that, under tension, anchors and suspends theworking sheath or protective sleeve that covers the neuroforaminalabrasion device;

FIG. 63 is a cross-sectional view through a patient's spine,illustrating a method and apparatus that, under tension, provides apercutaneous compression dressing over the abraded area. In thisillustration, the compression dressing is the same working sheath orprotective sleeve that had covered the neuroforaminal abrasion device;

FIG. 64 is a cross-sectional view of an embodiment of the tissue removalapparatus;

FIG. 65 is a cross-sectional view of an embodiment of a method for usingthe tissue removal apparatus;

FIG. 66A is a perspective view of a tissue modification device accordingto one embodiment of the present invention;

FIG. 66B is a perspective view of a portion of the tissue modificationdevice of FIG. 66A;

FIG. 66C is a top view of the portion shown in FIG. 66B;

FIG. 66D is a side view of the portion shown in FIGS. 66B and 66C;

FIGS. 66E and 66F are cross-sectional views of a portion of the tissuemodification device taken through lines A-A and B-B, respectively, shownin FIG. 66C;

FIG. 66G is a perspective view of a portion of the tissue modificationdevice of FIGS. 66B-66F, shown with a blade of the device in a closedposition according to one embodiment of the present invention;

FIG. 66H is a top view of the portion shown in FIG. 66G;

FIG. 66I is a side view of the portion shown in FIGS. 66G and 66H;

FIG. 67A is a perspective view of a tissue modification device accordingto one embodiment of the present invention;

FIG. 67B is a perspective view of a portion of the tissue modificationdevice of FIG. 4A;

FIG. 67C is a close-up, perspective view of a portion of the tissuemodification device of FIGS. 67A and 67B, showing a tissue modifyingmember according to one embodiment of the present invention;

FIGS. 68A-68D are cross-sectional views of a spine and demonstrate amethod for using a tissue modification device according to oneembodiment of the present invention;

FIG. 69A is a cross-sectional view of a portion of a patient's spine andback, with apparatus for modifying tissue in position for modifyingspinal tissue and with a distal portion of the apparatus anchoredoutside the patient according to one embodiment of the presentinvention; and

FIG. 69B is a cross-sectional view of a portion of a patient's spine andback, with apparatus for modifying tissue in position for modifyingspinal tissue and with a distal portion of the apparatus anchored insidethe patient according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments of tissue modification devices and systems, as wellas methods for making and using same, are provided. Although much of thefollowing description and accompanying drawing figures generally focuseson surgical procedures in spine, in alternative embodiments, devices,systems and methods of the present invention may be used in any of anumber of other anatomical locations in a patient's body. For example,in some embodiments, flexible tissue modification devices of the presentinvention may be used in minimally invasive procedures in the shoulder,elbow, wrist, hand, hip, knee, foot, ankle, other joints, or otheranatomical locations in the body. Similarly, although some embodimentsmay be used to remove or otherwise modify ligamentum flavum and/or bonein a spine to treat spinal stenosis, in alternative embodiments, any ofa number of other tissues may be modified to treat any of a number ofother conditions. For example, in various embodiments, treated tissuesmay include but are not limited to ligament, tendon, bone, tumor, cyst,cartilage, scar, osteophyte, inflammatory tissue and the like.Non-target tissues may include neural tissue and/or neurovascular tissuein some embodiments or any of a number of other tissues and/orstructures in other embodiments. In one alternative embodiment, forexample, a flexible tissue modification device may be used to incise atransverse carpal ligament in a wrist while inhibiting damage to themedian nerve, to perform a minimally invasive carpal tunnel releaseprocedure. Thus, various embodiments described herein may be used tomodify any of a number of different tissues, in any of a number ofanatomical locations in the body, to treat any of a number of differentconditions. For example, a device may be used to release of the lacinateligament of the tarsal tunnel of the foot and/or decompress theposterior tibial nerve, while inhibiting damage of the tibial nerve orits associated branches to perform a minimally invasive tarsal tunnelrelease procedure.

With reference now to FIG. 2A, a tissue modification device 10 accordingto one embodiment may suitably include a proximal handle 20 coupled witha shaft 12 having a proximal, rigid portion 13 and a distal, flexibleportion 14 on which one or more tissue modifying members 16 may bedisposed. A guidewire coupler 18 may be formed in (or attached to)flexible portion 14 at or near its distal end, for coupling with aguidewire 22, which in turn may be coupled with a guidewire handle 24(or “distal handle”), which may include a tightening lever 25 fortightening handle 24 around guidewire 22.

Device 10 is shown percutaneously placed in position for performing atissue modification procedure in a patient's spine, with variousanatomical structures shown including a vertebra V, cauda equina CE,ligamentum flavum LF, nerve root NR, facet F, and intervertebral foramenIF. Various embodiments of device 10 may be used in the spine to removeligamentum flavum LF, facet bone F, bony growths, or some combinationthereof, to help decompress cauda equina CE and/or nerve root NR tissueand thus help treat spinal stenosis and/or neural or neurovascularimpingement. Although this use of device 10 will not be continuouslyrepeated for every embodiment below, any of the described embodimentsmay be used to remove ligamentum flavum atone, bone alone, or acombination of ligament and bone in the spine to treat neuralimpingement, neurovascular impingement and/or spinal stenosis.

In one embodiment of a method for modifying tissue using device 10, adistal end of 22 guidewire may be placed into the patient, along acurved path between target and non-target tissue, and out of thepatient. A distal portion of guidewire 22 may then be coupled withguidewire handle 24, such as by passing guidewire 22 through a centralbore in handle 24 and tightening handle 24 around guidewire 22 viatightening lever 25 or other tightening means. A proximal end ofguidewire 22 may then be coupled with coupling member 18 and used topull distal shaft portion 14 between target and non-target tissues. Insome embodiments, device 10 may be advanced into the patientpercutaneously, while in alternative embodiments, device 10 may beadvanced through a small incision or larger incision. Once advanced intothe patient, flexible distal shaft portion 14 may be advanced along acurved path between the target and non-target tissues, and in someinstances may be pulled at least partway into an intervertebral foramenIF of the spine.

Proximal handle 20 and guidewire handle 24 may be pulled (or“tensioned”—solid/single-tipped arrows) to urge tissue modifying members16 against the target tissue (in this case, ligamentum flavum LF).Generally, tissue modifying members 16 may be fixedly attached to (orformed in) on one side or surface of distal portion 14, while anopposite side or portion of distal portion 14 faces non-target tissue,such as cauda equina CE and/or nerve root NR. The opposite side ofdistal portion 14 will generally be atraumatic and/or include anatraumatic cover, coating, shield, barrier, tissue capture member or thelike. With tensioning force applied to device 10, handles 20, 24 may beused to reciprocate device 10 back and forth (solid/double-tippedarrows) to cause tissue modifying members 16 to cut, remove, shred orotherwise modify the target tissue. In various embodiments, for example,target tissue may include only ligamentum flavum LF, only bone, or acombination of both.

Reciprocation and tensioning may be continued until a desired amount oftissue is removed. Removed target tissue, in some embodiments, may becollected, captured or trapped between tissue modifying members 16and/or in one or more tissue capture members or chambers (not shown).When a desired amount of target tissue has been removed, which may bedetermined, for example, by tactile feedback provided to the surgeon bydevice 10, by radiographic imaging, and/or by direct visualization (suchas in an open surgical case), guidewire 22 may be released from distalhandle 24, and device 10 may be removed from the patient's back. Ifdesired, device 10 may be passed into the patient's spine again foradditional tissue modification, and/or other devices may be passed intothe spine.

Additional details of various methods for inserting and using device 10are provided below. For further explanation of guidewire systems andmethods for inserting devices to remove or otherwise modify tissue,reference may also be made to U.S. patent application Ser. Nos.11/468,247 and 11/468,252, both titled “Tissue Access Guidewire Systemand Method,” and both filed Aug. 29, 2006, the full disclosures of whichare hereby incorporated by reference.

Referring now to FIG. 2B, in various embodiments, device 10 may be usedin parts of the body other than spine to remove target tissue TT whileavoiding harm to non-target tissue NTT. For example, target tissue TTmay include soft tissue adhering to bone, such as ligament and/orcartilage, and/or may include bone. Non-target tissue NIT may includeany nervous tissue, vascular tissue, an organ, or any other tissue thata surgeon may desire to leave unharmed by a surgical procedure. In oneembodiment, for example, device 10 may be used to perform a minimallyinvasive carpal tunnel release procedure by releasing the transversecarpal ligament without damaging the median nerve. In some embodiments,such a procedure may be performed percutaneously with or without anendoscope. In other embodiments, device 10 may be used to removecartilage and/or ligament from a knee or shoulder in a minimallyinvasive procedure. In yet another embodiment, device 10 may be used toperform a minimally invasive bunionectomy. Therefore, although thefollowing discussion focuses primarily on various uses of alternativeembodiments of device 10 in spine, any of a number of other anatomicalstructures may be operated upon in different embodiments. For example, adevice may be used to release of the lacinate ligament of the tarsaltunnel of the foot and/or decompress the posterior tibial nerve, whileinhibiting damage of the tibial nerve or its associated branches toperform a minimally invasive tarsal tunnel release procedure.

Referring now to FIG. 2C, in an alternative embodiment, a tissuemodification device 10′ may suitably include a proximal handle 20′,including a squeeze actuator 21′ and coupled with a shaft 12′ having aproximal, rigid portion 13′ and a distal, flexible portion 14′. One ormore tissue modifying members 16′ may be moveably coupled with one sideof flexible portion 14′, and a guidewire coupler 18′ may be formed in(or attached to) flexible portion 14′ at or near its distal end, forcoupling with a guidewire 22′ and thus a distal handle 24′ with atightening lever 25′.

In this alternative embodiment, squeeze actuator 21′ may be coupled withmoveable tissue modifying members 16′ by any suitable means, such thatactuating actuator 21′ (double-headed, solid-tipped arrow) causes tissuemodifying members 16′ to reciprocate back and forth (double-headed,hollow-tipped arrow). In use, therefore, device 10′ as a whole may beheld relatively stationary, while tissue modifying members 16′ arereciprocated. Proximal handle 20′ and rigid proximal shaft portion 13′may be used to steer device 10′ relative to target tissue, and of coursedevice 10′ may be moved in and out of the patient and/or the targettissue, but it may also be possible to hold device 10′ relativelystationary while reciprocating tissue modifying members 16′. In variousembodiments, squeeze actuator 21′ may be replaced with any suitablemechanical actuator, such as a trigger, lever or the like.

With reference now to FIG. 2D, in another alternative embodiment, atissue modification device 10″ may be similar to the previous embodimentbut may include, instead of squeeze actuator 21′, a button actuator 21″and a powered drive mechanism within handle 20″. Pressing buttonactuator 21″ may activate tissue modifying members 16″ to reciprocateback and forth to modify tissue. In various alternative embodiments,button 21″ may be replaced with any suitable actuator, such as atrigger, switch, dial or the like.

With reference now to FIG. 3A, in some embodiments tissue modificationdevice 10 may be provided as a system (or “kit”), including the variouscomponents described above in reference to FIGS. 2A and 2B. In someembodiments, a tissue modification system 15 or kit may suitably includedevice 10 of FIGS. 2A and 2B, as well as one or more additional devicesor components. For example, multiple guidewires 22 may be provided aspart of system 15. In some embodiments, system 15 may also include oneor more guidewire passage probes 32, 34 and a curved, flexible guidemember 36. In one embodiment, for example, an ipsilateral access probe32 and a contralateral access probe 34 may be provided. Curved guidemember 36 is generally configured to pass through a lumen in each ofprobes 32, 34 and includes an inner lumen through which guidewire 22 maybe passed. Guide member 36 may further include one or more depth marks35 to indicate to a surgeon when guide member 36 has been passed acertain distance into probe 32, 34 and a stop 37 to limit passage ofguide member 36 farther into probe 32, 34. In an alternative embodiment(not shown), such as might be used in a completely percutaneousprocedure, probes 32, 34 may be replaced with an introducer needle, suchas but not limited to a 14 gauge Touhy epidural needle or other size ortype of epidural needle. In such an embodiment, guide member 36 may bedesigned to pass through the bore of the needle. For further descriptionof various probe and guide member devices, reference may be made to U.S.patent application Ser. Nos. 11/468,247 and 11/468,252. Furtherreference may be made to U.S. patent application Ser. Nos. 11/457,416,titled “Spinal Access and Neural Localization,” and filed Jul. 13, 2006;and 60/823,594, titled “Surgical Probe and Method of Making,” and filedAug. 25, 2006, the full disclosures of which are hereby incorporated byreference.

Guidewire 22 may be made of any suitable material, such as nitinol orstainless steel, and may include a sharp distal tip 23, to facilitatepassage of guidewire 22 through tissue, and a proximal shaped end 27 forcoupling with guidewire coupler 18. Further details of various guidewire22 embodiments and distal handle 24 are provided, for example, in U.S.patent application Ser. Nos. 11/468,247 and 11/468,252, which werepreviously incorporated by reference.

FIGS. 3A and 3B show proximal handle 20 and shaft 12 in greater detailthan in previous figures. In the embodiment shown, four tissue modifyingmembers 16 are fixedly attached to one side of flexible distal shaftportion 14, each comprising grooved blades with bi-directional cuttingedges. In various alternative embodiments, any number of tissuemodifying members 16 may be included, such as from one to twenty tissuemodifying members 16. Furthermore, tissue modifying members 16 may haveany of a number of different configurations, some of which are describedbelow, such uni-directional blades, bi-directional blades, teeth, hooks,barbs, hooks, pieces of Gigli saw (or other wire saw), wires, meshes,woven material, knitted material, braided material, planes, graters,raised bumps, other abrasive surfaces, other abrasive materials,deliverable substances and/or the like.

In various embodiments, proximal shaft portion 13, distal shaft portion14, tissue modifying members 16 and guidewire coupler 18 may be made ofany suitable material (or materials), and may be made from one piece ofmaterial as a single extrusion or from separate pieces attachedtogether. For example, in many embodiments, all of shaft 12 andguidewire coupler 18 may be made from one piece of material, and tissuemodifying members 16 may be attached to distal shaft portion 14, such asby welding. In alternative embodiments, however, guidewire coupler 18may be a separate piece attached to distal shaft portion 14 and/ortissue modifying members 16 may be formed in (rather than attached to)distal shaft portion 14. In yet another embodiment, distal shaft portion14 may comprise a flat piece of material coupled with rigid proximalshaft portion 13, such as by welding. In some embodiments, shaft 12 maybe formed from one piece of material, and distal shaft portion 14 may beflattened to derive its shape and flexibility. In some embodiments, oneor more slits may be formed in distal shaft portion 14, to enhance itsflexibility. In some embodiments, proximal shaft portion 13 may have acylindrical shape. In some embodiments proximal shaft portion 13, distalshaft portion 14, or both may be hollow. Alternatively, any portion ofshaft 12 may be solid in some embodiments, such as to give proximalshaft portion 13 added rigidity.

In one embodiment, guidewire coupler 18 may include a slot 19, shaped toreceive and hold guidewire proximal shaped end 27. In variousembodiments, slot 19 may be located on the top surface of distal shaftportion 14, as shown, or on the bottom surface. For further descriptionof various embodiments of guidewire couplers, reference may be made toU.S. patent application Ser. Nos. 11/468,247 and 11/468,252. In someembodiments, an atraumatic cover 30 may be disposed over part of distalshaft portion 14, forming atraumatic edges 33 and an aperture 31 throughwhich tissue modifying members 16 protrude. Cover 30 may be made of anysuitable atraumatic material, such as any of a number of differentpolymers. In some embodiments, cover 30 may also serve to collect cuttissue.

FIG. 3B is a side view of device 10. Tissue modifying members 16 may beseen extending above atraumatic edges 33 of cover 30 and having cuttingedges facing both proximally and distally. In alternative embodiments,tissue modifying members 16 may have only uni-directional cutting edges,such as facing only proximally or only distally. In the embodimentshown, guidewire coupler 18 is formed as a loop at the distal end ofdistal shaft portion 14. Guidewire shaped end 27 may generally fit intoslot 19 (not visible in FIG. 3B) to reside within the loop of guidewirecoupler 18 during use. In other embodiments, guidewire coupler 18 maycomprise a separate piece attached to the top side or bottom side ofdistal shaft portion 14. Examples of such embodiments are describedfurther in U.S. patent application Ser. Nos. 11/468,247 and 11/468,252.

The various components of device 10, including proximal handle 20, shaft12, tissue modifying members 16, guidewire coupler 18, and cover 30, maybe fabricated from any suitable material or combination of materials.Suitable materials include, for example, metals, polymers, ceramics, orcomposites thereof. Suitable metals may include, but are not limited to,stainless steel (303, 304, 316, 316L), nickel-titanium alloy, tungstencarbide alloy, or cobalt-chromium alloy, for example, Elgiloy® (ElginSpecialty Metals, Elgin, Ill., USA), Conichrome® (Carpenter Technology,Reading, Pa., USA), or Phynox® (Imphy SA, Paris, France). Suitablepolymers include, but are not limited to, nylon, polyester, Dacron®,polyethylene, acetal, Delrin® (DuPont, Wilmington, Del.), polycarbonate,nylon, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK).Ceramics may include, but are not limited to, aluminas, zirconias, andcarbides. In some embodiments, one or more portions of shaft 12, forexample, may be reinforced with carbon fiber, fiberglass or the like.

Referring now to FIGS. 4A-4E, one embodiment of a method for modifyingtissue using flexible tissue modification device 10 is demonstrated ingreater detail. In these figures, a patient's skin, target tissue TT andnon-target tissue NTT are shown diagrammatically, rather than asspecific structures. In one embodiment, the method of FIGS. 4A-4E may beemployed in the spine, to remove ligamentum flavum, bone or both, withdevice 10 passing through an intervertebral foramen between twovertebrae, as shown in FIG. 2A. In other embodiments, other tissue inother areas of the body may be removed.

As shown in FIG. 4A, guidewire 22 with sharp tip 23 and shaped end 27may be passed into the skin, between target and non-target tissue, andout of the skin. Methods for passing guidewire 22 are described further,for example, in U.S. patent application Ser. Nos. 11/457,416, 11/468,247and 11/468,252, which were previously incorporated by reference. Asdescribed in those references, in various embodiments, guidewire 22 maybe placed using a percutaneous method, such as with a needle, or usingan open method, such as with a probe. In some embodiments, localizationof neural tissue, such as with nerve stimulation on a guidewire passingprobe or guidewire passing guide member may be used, to confirm thatguidewire 22 is passed between target and non-target tissue.

In some embodiments where the method is performed in the spine, one ormore substances or devices may be placed into the epidural space of thespine before or after placing guidewire 22, to create additional spacebetween target tissues, such as ligamentum flavum, and non-targettissues, such as cauda equina and nerve root. Substances may include,for example, any of a number of fluids or gels, such as radiographiccontrast medium. Devices may include, for example, a barrier or shielddevice. Injection of substances into the epidural space to create asafety zone is described in U.S. patent application Ser. No. 11/193,557(Pub. No. 2006/0036211), titled “Spinal Ligament Modification Kit,”assigned to X-Sten, Inc., and filed Jul. 29, 2005, the full disclosureof which is hereby incorporated by reference. Various barrier devicesfor placement in the spine are described, for example, in U.S. patentapplication Ser. No. 11/405,859, titled “Tissue Modification BarrierDevices and Methods,” and filed Apr. 17, 2005, the full disclosure ofwhich is hereby incorporated by reference.

Referring to FIG. 4B, distal handle 24 may be passed over sharp tip 23and tightened around guidewire 22, such as by moving tightening lever25. Distal handle 24 may be coupled with guidewire 22 at this point inthe process or at a later point, according to various embodiments.

As shown in FIG. 4C, guidewire 22 may next be coupled with proximaldevice portion 11, by coupling shaped guidewire end 27 (not visible)with guidewire coupler 18. In the embodiment shown, for example,guidewire shaped end 27 may be placed into coupling member 18(hollow-tipped arrow).

Referring to FIG. 4D, distal handle 24 may then be pulled (hollow-tippedarrow) to pull device 10 into the patient and to thus position tissuemodifying members 16 in contact with target tissue TT. In someembodiments, such as when device 10 is used in a spinal procedure andpasses through an intervertebral foramen, a surgeon or other physicianuser may use tactile feedback of device 10 passing into the foramen,such as when coupling member 18 and/or tissue modifying members passinto the foramen, to determine when tissue modifying members 16 arepositioned in a desired location relative to target tissue TT.Alternatively or additionally, a surgeon may confirm that a desiredplacement has been achieved by using radiographic imaging, such asfluoroscopy, direct visualization, such as in an open surgical case, ora combination of multiple methods.

In some embodiments in which device 10 is used in the spine to treatspinal stenosis and/or neural or neurovascular impingement, device 10may be passed into the patient and to a position for modifying tissuewithout removing any vertebral bone. More specifically, in someembodiments, device 10 may be advanced into the patient, through anintervertebral foramen, and out of the patient without removing bone.This is contrary to the majority of current surgical methods fortreating spinal stenosis, which typically include removal of at leastsome vertebral bone, such as performing a laminotomy or laminectomy, andwhich often remove significant amounts of vertebral lamina, spinousprocess, facet and/or pedicle bony tissue, simply to access the surgicalsite. In one embodiment, for example, device 10 may be advancedpercutaneously into the patient, used to remove ligamentum flavum only,and withdrawn from the patient, without removing any vertebral bone.

As shown in FIG. 4E, once tissue modifying members 16 are positioned asdesired, relative to target tissue TT, proximal handle 20 and guidewirehandle 24 may be pulled (hollow-tipped arrows) to urge tissue modifyingmembers 16 against target tissue TT (solid-tipped arrows). Whilemaintaining pulling/tensioning force, handles 20, 24 may be used toreciprocate device 10 back and forth (solid-tipped, double-headedarrows) to remove target tissue TT. During a procedure, rigid proximalshaft portion 13 may be used to help steer device 10, or morespecifically flexible distal shaft portion 14, relative to the targetTT. For example, rigid shaft portion 13 may be used to move flexibleportion 14 laterally or to pivot shaft 12 about an axis located alongflexible portion 14. In one embodiment, for example, rigid portion 13may be used to manipulate flexible portion 14 within an intervertebralforamen, such as by pivoting shaft 12 or moving flexible portion 14laterally in a caudal and/or cephalad direction, relative to thepatient. The rigidity of rigid proximal shaft portion 13 may generallyfacilitate such steering, as compared to a completely flexible device.

When a desired amount of tissue is removed, device 10 may be removedfrom the patient, such as by detaching guidewire handle 24 fromguidewire 22 and pulling proximal handle 20 to withdraw device 10 andguidewire 22 out of the patient. In some embodiments, device 10 or anadditional device may be reinserted into the patient and used in asecond location to remove additional tissue. For example, in a spinalstenosis treatment procedure, device 10 may be used to remove tissuefrom (and thus decompress) a first intervertebral foramen and then maybe removed and reinserted to remove tissue from a second foramen. Thisprocess may be repeated to remove tissue from any number of foramina. Inone embodiment, device 10 may include a guidewire lumen, so that aguidewire may be placed into a second foramen while device 10 is in theepidural space of the patient. Device 10 may then be removed along withthe first guidewire 22, attached to the second guidewire, and reinsertedinto the second foramen to remove tissue. In some embodiments, tissuemay be removed from device 10 before reinserting device 10 into thepatient to remove more tissue.

Referring now to FIGS. 5A-5C, a flexible distal portion 40 of a flexibletissue modification device is shown, in various views. In FIGS. 5A-5Cand 6-25, various alternative embodiments of a flexible distal portionof a tissue modification device are shown in a generally straightconfiguration. However, all embodiments shown are flexible and thus mayassume a curved configuration. The embodiments are shown in straightconfiguration for ease of illustration only.

In one embodiment, flexible distal portion 40 may include a substrate 42(or “flexible, distal shaft portion”), multiple tissue modifying members44 coupled with substrate 42, and an atraumatic cover 46 disposed oversubstrate 42 and forming an aperture 48 and atraumatic bumpers 49. FIG.5B is an end-on view of substrate 42 and one of cutting members 44,which includes multiple teeth 45. FIG. 5C is a side view of substrate 42and one of cutting members 44, showing that each cutting member 44 hastwo cutting edges 43 in this embodiment.

The embodiment of FIG. 5A includes three cutting members 44 comprisingblades with multiple teeth 45 with grooves between them. Cutting members44 in this and other embodiments may include any suitable material, suchas the materials listed previously above. Any number of cutting members44 may be used, such as from one to twenty cutting members in variousembodiments. Cutting members 44 may have any suitable height and my bespaced apart from one another at any suitable distances. In oneembodiment, for example, cutting members 44 may have a height designedto protrude just slightly above the height of bumpers 49, so thatcutting members 44 can cut tissue but do not protrude so high as toinhibit advancement or positioning of device in the patient. In someembodiments, cutting members 44 may be constructed as separate piecesand attached to substrate 42, such as by welding or gluing withadhesive. In some embodiments, cutting members 44 may be built bystacking layers of material to one another and attaching the stacks toform one piece. Cover 46 may be coupled with substrate using any knownor later invented manufacturing technique, such as thermoforming,injection molding, or the like.

In various alternative embodiments of distal portion 40 of FIGS. 5A-5C,as well as in all embodiments described below and alternatives thereto,any number of cutting members 44 may be used, cutting members 44 may bemade of any suitable material, and cutting members may be disposed alongsubstrate 42 in any configuration, pattern or the like. Therefore,various alternative materials, numbers, patterns and the like of cuttingmembers 44 will not be listed repeatedly for each alternativeembodiment.

Referring now to FIG. 6, in another embodiment, a distal portion of aflexible tissue modification device 50 may include substrate 42 and awire saw 52 coupled with substrate 42, such as by welding. In FIG. 6, aswell as in subsequent FIGS. 7-18, only a portion of each deviceembodiment including substrate 42 and one or more cutting members isshown, to simplify the drawing figures and description. Any of theseembodiments may also include an atraumatic cover and/or other features,but for simplicity's sake, these features are not shown. Referring tothe embodiment of FIG. 6, wire saw 52 may comprise any wire sawcurrently known or later invented, such as a Gigli saw, and may beattached to substrate 42 in any suitable pattern or configuration, suchas in an S-shape pattern, as shown, or a zig-zag, straight-line or otherpattern.

With reference to FIG. 7, in an alternative embodiment, a distal portionof a flexible tissue modification device 54 may include multiple piecesof wire saw 56 coupled with substrate 42. Again, these pieces of saw 56may be attached in any pattern and by any means, such as by welding, andmay comprise Gigli saw or other types of wire saw.

FIG. 8 shows a portion of another alternative embodiment of a flexibletissue modification device 58, in which abrasive materials 60, 62 areadhered to a surface of substrate. In some embodiments, only one typeand/or grain of abrasive material 60 or 62 may be used, while otherembodiments may include multiple types of material, multiple grains ofmaterial, or both. For example, in the embodiment shown, a finer grainof material 60 may be disposed at either end of a portion of coarsergrain material 62. Such a variation in grains may provide varyingdegrees of tissue modification and/or the ability to remove greateramounts of tissue with a coarser grain 62 and provide a smootherfinished surface to the tissue with the finer grain 60. In variousembodiments, any abrasive materials 60, 62 may be used, and thematerials may be adhered to substrate 42 via any method, such asadhering with adhesive or the like. One embodiment, for example, mayinclude abrasive materials such as those described in U.S. patentapplication Ser. No. 10/277,776 (Pub. No. 2003/0225412), titled“Surgical Ribbon File,” and filed Oct. 21, 2002, the full disclosure ofwhich is hereby incorporated by reference. In another embodiment,substrate 42 may be treated in such a way as to have an abrasivesurface, such as by sand blasting.

Referring to FIG. 9, in another alternative embodiment, a flexibletissue modification device 64 may include multiple tissue modifyingmembers 66, each including multiple, curved teeth 68. Cutting members 66may be made of stainless steel or other material(s). In someembodiments, cutting members 66 may be configured to primarily cutand/or shred ligamentous tissue, such as ligamentum flavum.

Referring to FIG. 10, in another alternative embodiment, a flexibletissue modification device 70 may include one tissue modifying member 72with vertically oriented blades 74 at opposite ends. Blades 74 may bedesigned, in one embodiment, specifically for cutting or slicingligamentous tissue, such as ligamentum flavum.

Referring to FIG. 11, in another alternative embodiment, a flexibletissue modification device 76 may include multiple tissue modifyingmembers 78, each with vertically oriented blades 80 at opposite ends.Blades 80 may each have a shark-tooth shape, with sharp edges onopposite sides. In one embodiment, blades 80 may be designedspecifically for cutting or slicing ligamentous tissue, such asligamentum flavum. Alternatively, or additionally, blades 80 may beconfigured to cut bone. In one embodiment, each blade 80 may have aheight approximately equal to or greater than a thickness of aligamentum flavum. Such a blade 80 may be positioned in the spine toextend through ligamentum flavum and contact bone. When reciprocated,such a blade 80 may cut ligamentum flavum alone or may cut ligamentumflavum tissue and then, when it is removed, may also cut bone. Such ablade height and configuration may facilitate lateral steering of device76.

Referring to FIG. 12, in another alternative embodiment, a flexibletissue modification device 82 may include multiple tissue modifyingmembers 84 formed as holes in substrate 42 with raised edges, such asare found on a cheese grater. The raised edges of cutting members 84 maybe sharp, to provide cutting. Any number of tissue modifying members 84my be included, they may have any desired size, and they may be formedon substrate in any pattern. In some embodiments, cut tissue may passthrough the holes of cutting members 84 and thus through substrate 42.In some embodiments, a tissue capture device or member may be coupledwith the back side of substrate 42 to collect cut tissue that passesthrough cutting members 84.

Referring to FIG. 13, in another alternative embodiment, a flexibletissue modification device 86 may include multiple tissue modifyingmembers 88 formed as upward-facing holes in substrate 42. The raisededges of cutting members 88 may be sharpened, to provide cutting. Anynumber of tissue modifying members 88 may be included. In someembodiments, cut tissue may pass through the holes of cutting members 88and thus through substrate 42. In some embodiments, a tissue capturedevice or member may be coupled with the back side of substrate tocollect cut tissue that passes through cutting members 88.

Referring to FIG. 14, in another alternative embodiment, a flexibletissue modification device 90 may include multiple tissue modifyingmembers 92 formed as raised flaps in substrate 42, with each flap 92including a sharpened cutting edge 94. Any number of tissue modifyingmembers 92 may be included. In some embodiments, cut tissue may passunderneath the flap-like cutting members 92 and thus through substrate42. In some embodiments, a tissue capture device or member may becoupled with the back side of substrate to collect cut tissue thatpasses through cutting members 92.

Referring to FIG. 15, in another alternative embodiment, a flexibletissue modification device 96 may include multiple tissue modifyingmembers 98 formed as rounded cutting devices coupled with substrate 42.In one embodiment, each cutting member 98 may include multiple ridges,divided by grooves. In one embodiment, cutting members 98 may have aspiral or screw-like configuration.

Referring to FIG. 16, in another alternative embodiment, a flexibletissue modification device 102 may include multiple tissue modifyingmembers 104 comprising thin, flap-like blades coupled with substrate 42,each cutting member 104 including a sharp blade edge 106. Any number,size and configuration of blades may be used.

Referring to FIG. 17, in another alternative embodiment, a flexibletissue modification device 108 may include multiple different types oftissue modifying members 110, 111. For example, one embodiment mayinclude one or more jagged tissue cutters 110 each having multiple,triangular, raised teeth 1112, and one or more bladed tissue cutters111, each having multiple blades 113. Teeth 112 and/or blades 113 may beconfigured specifically to cut ligamentum flavum tissue, bone, or both,in various embodiments.

Referring to FIG. 18, in another alternative embodiment, a flexibletissue modification device 114 may include substrate 42, a tissueengaging member 116 including multiple barbs 117 for hooks, needles orthe like), and one or more tissue cutting members 118, such as a raisedblade. In various embodiments, tissue engaging member 116 may beconfigured to hook, snag, grab or otherwise engage soft tissue, such asligamentum flavum, and pull or stretch such tissue as it is pulled orpushed across the tissue. Tissue cutting member 118 may follow behindtissue engaging member 116 and cut the stretched/pulled tissue. Suchstretching or pulling of tissue before cutting may facilitate or enhancetissue cutting.

Referring to FIG. 19, in another alternative embodiment, a flexibletissue modification device 122 may include a wire mesh 124 coupled withmultiple supporting structures 126 and an atraumatic material 128 on oneside. All components may be made of any suitable material, such as thoselisted previously.

Referring to FIG. 20, in another alternative embodiment, a flexibletissue modification device 130 may comprise a hollow, flattened shaft132, having central chamber or lumen 134, into which multiple grooves136 may be cut. An edge of each groove 136 may be raised and sharpenedto form a blade edge 138, thus forming a multiple, bladed tissuemodifying members. Tissue cut by blades 138 may pass under blades 138 tocollect within lumen 134 and may thus be transported out of the patient.

Referring to FIG. 21, in another alternative embodiment, a flexibletissue modification device 140 may include multiple tissue modifyingmembers 142 formed as holes in substrate 42 with raised edges, such asare found on a cheese grater. The raised edges of cutting members 142may be sharpened, to provide cutting. Any number of tissue modifyingmembers 142 may be included. In some embodiments, cut tissue may passthrough the holes of cutting members 142 and thus through substrate 42.In some embodiments, a tissue collection member 144, forming a tissuecollection chamber 148, may be coupled with the back side of substrate42 to collect cut tissue that passes through cutting members 142. Tissuecollection member 144 may also serve as an atraumatic tissue protectionmember and may include, for example, side bumpers 146 to avoid damagingnon-target tissue with sharp edges of device 140. In some embodiments,tissue collection member 144 may be strengthened by multiple fibers 145,such as wires or carbon fibers.

Referring to FIG. 22, in another alternative embodiment, a flexibletissue modification device 150 may include multiple sections 152 linkedtogether via linkages 154 to form a flexible device configurationanalogous to that of some watch bands. A tissue modifying member 156having a cutting edge 158 may be disposed on one side of each section152 to cut tissue.

In various embodiments, any given flexible tissue modification devicemay act on tissue in a number of different ways, such as by cutting,ablating, dissecting, repairing, reducing blood flow in, shrinking,shaving, burring, biting, remodeling, biopsying, debriding, lysing,debulking, sanding, filing, planing, heating, cooling, vaporizing,delivering a drug to, and/or retracting target tissue. For example, manyof the devices described above may also optionally be loaded with adrug, bone wax, gel foam, or the like, which may be deposited during atissue modification procedure. Any suitable drug may be delivered viathe devices in various embodiments, such as but not limited to thrombin,NSAID, local anesthetic or opioid. In some embodiments, devices may alsodeliver an implant, such as a stent-like implant for maintaining patencyof decompressed intervertebral foramen, a rivet, staple or similardevice for retracting ligamentum flavum tissue, a tissue dressing, orthe like. In some embodiments, devices may cool or freeze tissue foranalgesia or to change the tissue's modulus of elasticity to facilitatetissue modification. Some embodiments of devices may also include avisualization and/or diagnostic component, such as an ultrasound, MRI,reflectance spectroscopy, fiber optic, endoscope, charge-coupled device(CCD), complementary metal-oxide semiconductor (CMOS) or other device.

Any of the devices described herein may also optionally include one ormore components for neural identification and/or localization. Forexample, in some embodiments, a flexible tissue modification device mayinclude one or more nerve stimulation electrodes on a backside undersideof the device (i.e., a side designed to be atraumatic and facenon-target tissue). The electrode(s) may be used to confirm that theatraumatic side of the device is in contact with non-target neuraltissue, thus also confirming that the tissue modification members of thedevice are facing target tissue. In some embodiments, the devices mayalso include one or more electrodes on an upper surface, at or near thetissue modification members, to further confirm a desired placement ofthe device. For further description of such neural localization devicesand methods, reference may be made to U.S. patent application Ser. No.11/457,416, which was previously incorporated by reference.

With reference now to FIG. 23, in another alternative embodiment, atissue modification device 1160 may suitably include a proximal handle1170 coupled with an elongate body 1162 (or “shaft”) having a proximal,rigid shaft portion 1163 and a distal, flexible portion 1164 from whichmultiple blades 1166 may extend. A guidewire coupler 1168 may be formedin (or attached to) flexible portion 1164 at or near its distal end forcoupling with a guidewire 1172, which in turn may be coupled with aguidewire handle 1174 (or “distal handle”). Distal handle 1174 mayinclude a tightening lever 1175 for tightening handle 1174 aroundguidewire 1172. In one embodiment, device 1160 may have many of thecharacteristics and be used in much the same way as embodimentsdescribed above.

In FIG. 23, device 1160 is shown passing into a patient, along a curvedpath between a generic soft tissue/bone combination and nearbynon-target tissue NTT, and back out of the patient. In one embodiment,device 1160 may be passed into a patient, through an intervertebralspace of the patient's spine (between ligamentum flavum andneural/neurovascular tissue), and back out of the patient, as describedin detail above with reference to alternative embodiments. Once device1160 is in place for modifying a target tissue, such as soft tissueand/or bone, handles 1170, 1174 may be pulled (hollow-tipped arrows) toapply force and thus urge blades 1166 into soft tissue (single-headed,solid-tipped arrows). Device 1160 may then be reciprocated(double-headed, solid-tipped arrows), while maintaining some or all ofthe pulling force, to remove or otherwise modify the target soft tissueand/or bone. As mentioned previously, before reciprocating device 1160to remove tissue, in some embodiments the device may be used tostimulate nearby nerve tissue, such as with an electrode coupled withthe back and/or front side(s) of flexible portion 1164. Such nervestimulation may help confirm that device 1160 has been placed in adesired location for treatment and may be monitored usingelectromyography (EMG), visual observation of muscle twitch and/or thelike.

Referring to FIG. 24, in one embodiment a tissue modification device1180 may include a proximal handle 1189 coupled with one end of anelongate body 1182, which includes a proximal rigid shaft portion 1183and a distal flexible portion 1184. Multiple blades 1186, 1186′ extendfrom a first side of flexible portion 1184, while a second sideapproximately opposite the first side is substantially atraumatic toinhibit damage to non-target tissues during a tissue modificationprocedure. Flexible portion 1184 may also include a guidewire coupler1188 at its distal end. In various embodiments, a suitable combinationof blades 1186, 1186′ may be included on a given tissue modificationdevice. For example, device 1180 includes four pointed-tip blades 1186and two flat-top blades 1186′. Various blades may be configured toperform one or more of a number of functions. For example, pointed-tipblades 1186 may be ideal for eating through soft tissue and bone, whileflat-top blades 1186′ may be best for cutting through soft tissue andriding along a bone surface to help steer or guide device 1180. In someembodiments, all blades on a device may be configured for optimal softtissue cutting, such as cutting of ligamentum flavum tissue in thespine, while in other embodiments all blades may be configured foroptimal bone cutting, such as vertebral bone. Other alternativeembodiments may include a combination of blade shapes and configurationsto provide multiple different types of cutting. Further discussion ofblades combinations and configurations are included in application Ser.No. 11/687,558, filed Mar. 16, 2007, and entitled “Flexible TissueRemoval Devices and Methods”, the full disclosure of which isincorporated herein by reference.

With reference now to FIG. 25, a perspective view of a portion of analternative embodiment of a tissue modification device 1190 shows arigid shaft portion 1193 extending to a flexible portion 1194 withpointed-tip blades 196, flat-top blades 1196′, and a guidewire coupler1198. In the embodiment shown, and as is described in further detailbelow in relation to another embodiment, some or all blades 1196′ may beangled, relative to a longitudinal axis of the elongate body andflexible portion 1194 of device 1190. Angling blades 1196′ may cause orfacilitate lateral movement of device 1190 along a target tissue asdevice 1190 is reciprocated back and forth to modify the tissue, thusproviding for wider or more complete tissue modification/removal.

Referring now to FIGS. 26A and 26B, a tissue modification device 402 hasa rigid proximal shaft portion 404 from which a flexible portion 406extends axially. A plurality of tissue modification elements in the formof blades 408 extend from a first surface 410 of flexible portion 406,as described above. Flexible portion 406 is advanced into a patient bodyso that first surface 410 is bent over a target tissue, with the targettissue here comprising both ligament 412 and bone 414. First surface 410of flexible portion 406 is wrapped over an at least partially convexsurface 416, with the convexity of the surface defining an inwardorientation 418 and an outward orientation 420 (see FIG. 40B). Hence,axial tension 422 on the flexible portion 406 causes the first surface410 to move inwardly toward the target tissue 412, 414.

Referring still to FIGS. 26A and 26B, the surface 416 of the targettissue need not, and often will not, be substantially cylindrical, butwill often instead have portions that are more inward 418, and otherportions that are more outward 420. For example, a first portion orregion of the surface 416 adjacent a first edge 424 of flexible portion406 may be significantly more outward 420 than a region of the surfacethat is adjacent an opposed edge 426 and engagement between the flexibleportion and tissue surface. As a result of the axial tension 422 in theflexible portion 406, this difference can cause the flexible portion torotate about its central axis. Continued reciprocation of the flexibleportion when its rotational orientation is not adequately controlledcould cause an edge 426 of the flexible portion to cut laterally intotarget tissues as illustrated in FIG. 26B, or even inadvertent flippingof the flexible portion which might expose non-target tissue 430 todamage from the cutting blades along first surface 410, rather thaneffecting controlled volumetric removal of the target tissue.

To inhibit uncontrolled rotation of the flexible portion 406, the rigidshaft of proximal portion 404 significantly improves the control overboth the orientation and position of the flexible portion, in part bytransmitting torque 432 from the proximal handle to the treatment sitewithin the patient. By rotating (or restraining) the proximal handleabout the axis of the shaft, torque is transmitted down the shaft and tothe flexible portion adjacent the target tissue. The torque can betransmitted so as to inhibit roiling or flipping of the flexibleportion, and can also be used to intentionally alter an orientation ofthe flexible portion and tissue modifying members. The proximal handleand/or proximal portion may have an asymmetric shape or some asymmetricindicia that identifies the orientation of the tissue modifying membersto enhance the physician's control over the orientation of tissue beingmodified and/or removed.

Referring now to FIGS. 27A and 27B, additional aspects of the structureand use of rigid shaft proximal portion 404 to control the location andorientation of distal flexible portion 406 can be understood. Asgenerally described above, tissue modification tool 402 is generallypositioned for use with rigid portion 404 extending a proximal handle440 through an open or minimally invasive surgical axis site to flexibleportion 406, with the flexible portion often extending distally from anaxis 442 of the proximal portion. The distal flexible portion 406 alsohas a central axis which extends around a target tissue to a distal endthat is coupled to a guidewire 444 extending out of the patient, with adistal handle 446 being axially affixable to the guidewire so thattension can be applied to the flexible portion 406 by pulling upward onthe proximal and distal handles 440, 446.

As described above, torquing the shaft of rigid portion 404 about ifsaxis using handle 440 (as schematically illustrated by arrows 448) canhelp to orient the tissue treatment member(s) along the first surface410 of flexible portion 406 toward a target region of the target tissue.Additionally, it will often be desirable to shift flexible portion 406laterally relative to its central axis, that is, into and/or out of theillustration of FIG. 27B. Handle 440 can be used to help move flexibleportion 406 using one or both of two techniques. First, handle 440 canbe pushed laterally relative to the axis 450 of the rigid proximal shaftportion 404 as illustrated by arrows 452. Where handle 440 laterallytranslates the shaft without rotating of the shaft, end 454 of rigidportion 404 may also translate laterally, thereby laterally shifting theflexible portion 406. Alternatively, handle 440 may be used to pivot therigid portion 404 about an effective pivot point 456 (as schematicallyillustrated by curving arrows 458), similarly effecting lateral movementof the end 454 of the rigid portion within the patient. Some combinationof lateral movement of the overall rigid portion 404 will often becombined with some pivoting of the rigid portion. The pivot point 456 isnot necessarily at a fixed location in space, and may move somewhat asthe tissues adjacent the tissue modification tool 402 are displacedand/or compressed.

As described above, guidewire 444 advantageously allows tension to beapplied to a distal end 460 of flexible portion 406, optionally allowingthe flexible portion to be shifted and/or positioned along its curvingaccess for treatment of a target tissue, as well as allowing distractionof target tissues, reciprocation of the tissue modification elements andflexible portion against a target tissue, and the like. To enhancelateral and rotational control over the flexible portion 406, andparticularly the length of the flexible portion close to its distal end460, a second rigid shaft 462 may be affixed to distal handle 446. Thesecond shaft 462 may have a central lumen that receives guidewire 444therethrough. Second shaft 462 may then be manipulated as describedabove regarding the rigid portion 404, allowing the distal end 460 ofthe flexible portion to be shifted in coordination with the shiftingeffected by the rigid portion 404. This may enhance overall control overthe lateral movement of flexible portion, optionally using the pivotingand/or lateral movement techniques described above. The second rigidshaft 462 will often have a distal end with a profile suitable foradvancing distally over guidewire 44 toward the target tissue, and mayalso torquably engage the distal end of flexible portion 406 so as toallow the distal end to be torqued about the longitudinal axis of theflexible portion and guidewire (such as by providing a slot in theinserted end of second shaft 462 to torquably receive the distal end ofthe flexible portion).

Referring now to FIGS. 28A-28E, it will often be desirable to removetarget tissue from a tissue region 1259 which is wider than an adjacenttissue modification device 1260. Additionally, it may be desirable toreorient the tissue modification members carried by a flexible portionof a tissue modification device 1260 so as to treat portions of thetarget tissue that are at different angles. As described above,tensioning of tissue modification device 1260 using the proximal anddistal handles can urge the tissue modifying members toward a firstregion of the target tissue, such as the region being engaged by blades1262, 1262′ in FIG. 28B. As this tissue is removed, the tension willtend to keep the tissue modification device 1260 at the removed tissuelocation. Optionally, the orientation of the tissue modification device1260 may be rotated about a central axis of the flexible portion of thetissue modification device by rotation of rigid portion 404 (see FIGS.26A, 27A), resulting in lateral rotation of the flexible portion andtissue modification elements carried thereby in a counter-clockwisedirection (see FIG. 28C) wherein a clockwise direction (see FIG. 28D).Additionally, lateral translation and/or pivoting of the rigid portion404 about pivot point 456 may be used to laterally shift or translatethe tissue treatment device 1260.

Lateral shifting of the flexible portion may be facilitated (forexample) by including tissue modification devices or blades havingsufficient length to extend through ligament target tissue such as theligamentum flavum, and by including tips on at least some of the tissuemodification devices or blades that are large enough to avoidpenetrating into underlying bone. This may allow the flexible substrateto ride over the tough ligament, facilitating lateral movement of theoutermost blades into target ligament tissues. Lateral shifting of theflexible portion may also be facilitated by a flexible substratestructure which is relatively stiff in one lateral orientation(specifically, along the major surfaces) and more flexible in anotherlateral orientation (transverse to the major surfaces, so as to allowthe flexible member to bend over the target tissue with a major surfaceoriented toward the target tissue). Advantageously, such selectivelateral flexibility and lateral stiffness can be readily provided by athin, flat substrate having a cross-section that includes a much largermoment in one orientation (for example, bending in the plane of themajor surfaces) than another (for example, bending in the plane of thesmaller edges).

Still with reference now to FIGS. 28A-28E, a method according to oneadditional embodiment can be understood for removing tissue using atissue modification device 1260. FIG. 28A is an end-on, diagrammaticrepresentation of an intervertebral foramen IF, showing vertebral bone,ligamentum flavum LF and nerve root N, with device 1260 passing throughthe foramen IF between nerve root N and ligamentum flavum. Device 1260may have some blades 1262 oriented at approximately a 0 degree anglerelative to the longitudinal axis of device 1260, while other blades1262′ may be angled, relative to the longitudinal axis.

In FIG. 28B, device 1260 has been pulled upward (hollow-tipped arrows)to urge blades 1262, 1262′ into ligamentum flavum LF so that at leastone of blades 1262, 1262′ contacts vertebral bone. In some embodiments,some or all of blades 1262, 1262′ may have a height approximating athickness of an average ligamentum flavum LF.

Referring to FIG. 28C, when device 1260 is reciprocated back and forthalong its long axis, ligamentum flavum LF tissue is removed in one areaof the intervertebral foramen IF. As device 1260 is reciprocated, angledblades 1262′ may steer or guide device 1260 laterally in theintervertebral foramen IF (hollow-tipped arrow). In some embodiments,for example, device 1260 may steer to one side when the device is pulledin one direction and steer to the other side when the device is pulledin the opposite direction.

In FIG. 28D, device 1260 has moved toward the opposite lateral side ofthe intervertebral foramen IF (hollow-tipped arrow) to remove additionalligamentum flavum. LF tissue. In some embodiments, any or all blades1262, 1262′ of device 1260 may have flat tops, which may help blades1262, 1262′ to slide or “skate” across the surface of bone as device1260 is reciprocated to cut through soft tissue. This sliding or skatingmotion may also help device 1260 move from side to side within theintervertebral foramen W.

In FIG. 28E, much of the ligamentum flavum LF has been removed, andblades 1262, 1262′ are in a position to treat bone. In some cases, aphysician may choose to continue using device 1260 to remove bone, whilein other cases a physician may wish to remove mostly or exclusivelyligamentum flavum LF tissue. In various embodiments, the physician maydetermine when a desired amount of soft tissue and/or bone is removed byusing tactile feedback from device 1260, by removing device 1260 toexamine tissue trapped in device 1260, by radiographic visualizationsuch as fluoroscopy, by use of one or more sizing probes or otherinstruments to gauge the size of the intervertebral foramen IF, or anycombination of such methods.

When a desired amount of tissue has been removed, device 1260 may beremoved from the patient to complete the procedure. As mentioned, insome embodiments, device 1260 may be used to remove only ligamentumflavum LF tissue and then removed from the patient to end the procedure.In alternative embodiments, device 1260 (or a differently configureddevice) may be used to remove both soft tissue and bone. In yet anotheralternative embodiment, a first device (for example, device 1260) may beused to remove ligamentum flavum LF tissue, the first device may beremoved from the patient, and a second device may be inserted and usedto remove bone. Thus, in some embodiments, two different devices may beused in one procedure, with one device optimized for soft tissue removaland another device optimized for bone removal.

With reference now to FIGS. 29-32, various embodiments of bladestructures are shown. For example, in an embodiment as in FIG. 29, ablade structure 1270 may include two blades 1272 extending substantiallyvertically from abuse 1274. Base 1274 may provide a surface forattaching blades 1272 to one side of a tissue modification device.Blades 1272 may have beveled cutting edges and pointed tips, as shown.

In an alternative embodiment, as in FIG. 30, a blade structure 1280 mayagain include two blades 1282 extending vertically from a base 1284. Inthis embodiment, blades 1282 have beveled edges and a flat, beveled top.

In another alternative embodiment, as in FIG. 31, a blade structure 1290may include any number of blades 1292 coupled with a base 1294. In thisembodiment, twelve blades 1292 are coupled with base 1294, and base 1294has aback-and-forth or zig-zag configuration.

In another alternative embodiment, as in FIG. 32, a blade structure 1300may include eight, flat-top blades 1302 (or any other suitable number)coupled with a base 1304 having a diagonal configuration. When base 1304is attached to a surface of a tissue modification device, blades 1302will typically be angled due to the diagonal configuration of base 1304.

In various alternative embodiments, any of the tissue modificationdevices and method described above may be used in combination with oneor more vertebral distraction devices. In one embodiment, for example,an interspinous implant such as the X STOP® implant (offered by St.Francis Medical Technologies, Inc., Alameda, Calif., www.sfmt.com) maybe inserted between adjacent vertebrae, and then access devices and/ortissue removal devices described herein may be used to remove orotherwise modify spinal tissue. Such an implant may be inserted and leftplace after a procedure, while in alternative embodiments a distractiondevice may be used only during a tissue removal procedure. Variousembodiments and aspects of such distraction/tissue removal combinationsare described in greater detail in U.S. Provisional Patent ApplicationSer. No. 60/884,371, titled “Spinal Stenosis Treatment Methods andApparatus,” filed Jan. 10, 2007, the full disclosure of which is herebyincorporated by reference.

The method of modifying the spinal anatomy can include confirming properplacement of the surgical apparatus. Confirming proper placement caninclude confirming proper placement with a nerve stimulator. Confirmingproper placement with a nerve stimulator further comprises confirmingproper placement with stimulation leads placed on a tissue remodelingside of the surgical apparatus. The method of modifying the spinalanatomy can include confirming proper placement of the surgicalapparatus or barrier with a nerve stimulator having stimulation leadsplaced on a tissue remodeling side of the barrier or on a back side ofthe barrier.

The apparatus can be configured for use with a visualization element.The visualization element can be chosen from the group consisting of anepidural endoscope, a fluoroscope, ultrasound, XRay, MRI andcombinations thereof. The apparatus can have a nerve stimulator tofacilitate proper placement of the barrier. A conductive element can beincluded on a tissue modification side of the barrier or on a backsideof the barrier to facilitate nerve localization. A working surface ofthe tissue remodeling device can have neurostimulation capabilities,thereby allowing for a positive and negative control in localizingneural tissue prior to tissue removal.

The method can include confirming proper placement of the tissueabrasion device. Confirming proper placement of the device can includeconfirming proper placement with a nerve stimulator. Confirming properplacement with a nerve stimulator can include confirming properplacement with a nerve stimulator having stimulation leads placed at alocation chosen from the group consisting of a non-abrasive side of thetissue abrasion device, a back side of a protective sleeve or coverplaced over the tissue abrasion device, an abrasive side of the tissueabrasion device, a working side of the tissue abrasion device, andcombinations thereof. Confirming proper placement can include confirmingplacement via a modality chosen from the group consisting offluoroscopic, MRI, CT, infrared, ultrasound imaging, surgicaltriangulation, and combinations thereof.

The apparatus can have a protective cover disposed about the tissueabrasion device, where the protective cover is configured to limitexposure of an abrasive surface of the device to areas where tissueremoval is desired. The apparatus can have a nerve stimulator incommunication with the tissue abrasion device to facilitate properplacement of the device.

As discussed previously, variations of the present invention preferablyprovide for access, neural protection and/or decompression for treatmentof spinal stenosis. With reference to FIGS. 33 and 34, methods andapparatus for obtaining access to the neural foramen utilizing opensurgical variations of the present invention are described. FIG. 33Aillustrates two variations of access element 184. In the first variation(33A-1), access element 184 comprises cannulated probe 186,illustratively an elevator probe having first and second lumens 188 and190. Visualization element 192, such as an epidural endoscope, may beadvanced through or coupled to lumen 188 to provide visualization at thedistal tip of probe 186.

The method can include, prior to selective removal of the impingingtissue, confirming proper placement of the neural protection element andthe tissue removal device. Confirming proper placement can includelocalizing the nerve root with a stimulation waveform.

The neural protection element can be an element configured for deliveryvia the access element. The neural protection element can be configuredfor transforaminal placement between impinging tissue and a nerve root.The access element can be configured for transforaminal placement. Theneural protection element can have a sheath having a window. The tissueremoval device can be configured for placement within the sheath suchthat tissue removal elements disposed on a tissue removal surface of thedevice are locally exposed within the window. The window can beconfigured for transforaminal placement.

In the second variation (FIG. 33A-2), probe 186 of access element 184comprises single lumen 188′. Visualization element 192, as well ascannula 194 or curved guide wire 4 described hereinafter, may beadvanced through the unitary lumen—either in parallel or in sequence.Alternatively, the visualization element may be omitted or may beattached directly to the probe. As will be apparent, access element 184may comprise any desired number of lumens.

In FIG. 33B, the dual lumen variation of access element 184 has beenplaced through a surgical incision or cut-down in proximity to neuralforamen 110 while under optional visualization from element 192.Visualization may facilitate access via a minimally invasive or keyholesurgical cut-down, as opposed to a fully open approach. Directvisualization alternatively or additionally may be utilized.

As seen in FIG. 33C, with probe 186 properly positioned, atraumaticcurved tube, introducer or cannula 194 may be advanced through lumen188′ of the probe and driven laterally to cannulate the neural foramen110. Cannula 194 optionally may be configured to deliver a stimulationwaveform at or near its distal tip for monitoring proximity to the nerveroot during cannulation of the foramina with the cannula. A preferablystraight, flexible guide wire 4 or needle, which optionally comprisessharpened tip, then may be advanced through cannula 194 and drivenposteriorly through the skin of the patient's hack, as in FIG. 33D.Alternatively, a second surgical incision and or cut-down may be formedat or near the exit of the neural foramen for grasping the guide wireand pulling it through. With access guide wire 4 positioned through andacross the neural foramen, probe 186 may be removed, as in FIG. 33E.This leaves the guide Wire 4 in place to provide access for, e.g.,neural protection and tissue removal apparatus, as describedhereinbelow.

With reference to FIG. 34, an alternative method for obtaining openaccess is described. As seen in FIG. 34A, curved guide wire 22 may beadvanced through lumen 188′ of probe 186, such that the guide wire 22passes through the neural foramen 110, encircles the facet 12 andreemerges in the surgical field. Guide wire 22 optionally may beconfigured to deliver a stimulation waveform at or near its distal tipfor monitoring proximity to the nerve root during passage of the wirethrough the foramen 110. The needle may, for example, be insulated atregions other than the distal tip. With the wire encircling the facet12, probe 186 then may be removed, as seen in FIG. 34B, leaving accessguide wire 22 in place to provide access for selective removal ofimpinging tissue.

Access also may be achieved in a percutaneous fashion. For example,access may be achieved via an access element comprising an epiduralneedle or probe, or via an epidural endoscope having a working channel,that is positioned within the epidural space. In one variation, a curvedatraumatic needle or cannula may be advanced through the percutaneousaccess element and driven laterally to cannulate the neural foramen. Apreferably straight, flexible guide wire or needle then may be advancedthrough the curved needle and driven posteriorly through the skin of thepatient's back. In an alternative variation, a curved guide wire may beadvanced through the percutaneous access element and passedtransforaminally. Percutaneous access optionally may be aided by the useof image guidance, an epidural endoscope or any other visualizationtechnique.

FIG. 35 shows a percutaneous method and apparatus for obtaining accessfor selective surgical removal of tissue. Access element is disposedwithin epidural space 42. Access element may comprise, for example,epidural needle 2, an epidural trocar, an epidural endoscope, etc. Theneedle tip is anterior to the ligamentum flavum 10, but still posteriorto the dura 46 in the posterior epidural space 42.

FIG. 36 illustrates a preferred method of cannulating the neuralforamina, where an atraumatic curved tube or cannula 16 (e.g., blunt,curved needle composed of memory material) is passed through thestraight epidural needle 2 (alternatively, a stiff epidural catheter, orsteerable guidewire may be inserted through the needle for this step) tocannulate the neural foramen NF. The curved needle 16 is flexible enoughto be passed through the straight epidural needle 2, but is made of amemory material that returns it to its curved configuration upon when itis passed into tissue. The second needle 16 (alternatively, a steerable,stiff catheter or guidewire), is advanced through the epidural space 42,possibly passing through a portion of the ligamentum flavum 10, towardsand then through the ipsilateral or contralateral neural foramen 110.The surgeon may use any combination of tactile feet, image guidance,direct visualization, and/or fiberoptic visualization to ensure that thecurved element 16 is driven through the neural foramen, anterior to thefacet (zygapophysial) joint complex 12, but posterior to the nerve root62 or ganglion. As discussed previously, the cannulas may be configuredto stimulate and monitor response of the nerve root as a safetyprecaution during cannulation of the foramen.

Once the curved element is in position through the neural foramen, thesurgeon subsequently passes a smaller gauge straight and sharp flexibleguidewire 4 (or needle), as in FIG. 37 through the lumen of the largercurved needle that is in position through the neural foramen 110, untilit exits into the tissue lateral to the neural foramen (FIG. 37). Thisstraight wire 4 or straight needle exits the curved element with its tipfacing in a posterior or posterior-lateral direction. It is advancedfurther in this direction, passing to, and then through the skin of thepatient's back 70, as in FIG. 37. Access element 2 and cannula 16 thenmay be removed, as in FIG. 38, leaving access guide wire 4 in placetransforaminally to provide access to the lateral recess and neuralforamen.

As an alternative to deploying cannula 16 through access element 2, thecannula 16 may be delivered over the access element. As yet anotheralternative, upon placement of the access element in the epidural space,a stiff rod may be advanced through the lumen of the access element, andthe access element may be removed. Cannula 16 then may be deployed overthe stiff rod, which then may be removed from the lumen of the cannulaand replaced with guide wire 4.

In some alternative embodiments, a steerable needle or wire 18 is placedthrough the neural foramina 110 from the lateral towards the medial sideof the foramen 110. This lateral to medial neuroforaminal approach maybegin with a curved, blunt wire through a straight needle (as describedin the previous technique), or using a curved needle technique, asteerable guidewire technique, a needle-through-a-needle technique, orcommon variations thereof. While a loss of resistance technique is notas helpful with this transforaminal approach to the epidural space 42,as it was in the previously described posterior approach to the epiduralspace 42, the method is, in many other aspects, otherwise similar to themethod illustrated in FIGS. 35-42.

In FIG. 43, straight wire or needle 4 is driven through curved needle 16disposed in working channel 50 of double barrel epidural needle. Thisstraight wire or needle 4 is advanced until it has penetrated throughthe skin and out of the patient's body. The straight wire preferably hasa sharp tip. In FIG. 44, curved needle 16 is withdrawn from workingchannel 50, leaving straight wire or needle 4 in place. Then, as seen inFIG. 45, the epidural needle and working channel may be withdrawn fromthe patient, or, in an alternative embodiment, when using a detachableworking channel 50, the working channel alone may be withdrawn from thepatient, leaving straight wire 4 in place. In FIG. 46, straight wire 4is hooked to abrasion device 14 and/or the abrasion device's protectivesleeve 6. In FIG. 47, the abrasion device 14 and/or the device'sprotective sleeve are pulled into position by wire 4 as the wire isremoved. In FIG. 48, wire 4 has been completely removed, and theabrasion device 14 and its protective sleeve 6 are property positionedfor tissue resection, anterior to the facet 12 and ligamentum flavum 10.

In an open surgical variation, the abrasive element 14 and its cover 6may be placed through the surgical incision, from an interlaminar,translaminar, or neuroforaminal approach. Visualization and placementmay be aided via partial or complete laminectomy, facetectomy, orligamentectomy. Methods for threading the neural foramina include, butare not limited to the use of a wire, blunt needle, probe, endoscope, orsuture. After spinal neuroforaminal placement, the abrasion device 14 isused to selectively remove tissues that impinge on the neurovascularstructures within the lateral recess 108 and neural foramen 110, on theanterior side of the facet joint 12. In an open approach, as with apercutaneous approach, the device may be inserted through a needle,optionally under image guidance or with the aid of an epiduralendoscope. Once placed through the neural foramina 110 of the spine,around the anterior border of the facet joint 12, and anterior to theligamentum flavum 10, the medical practitioner may enlarge the lateralrecess and neural foramina via frictional abrasion, i.e., by sliding theabrasive surface across the tissue to be resected (e.g., far lateralligamentum flavum, anterior and medial facet, osteophytes). The abrasiondevice alternatively or additionally may be placed through the neuralforamen 110 anterior to the facet joint 12, but through or posterior tothe ligamentum flavum 10. The medical practitioner controls the forceand speed of the abrasive surface against the tissue to be removed,while optional protective covers, tubes or sleeves 6 help limit the areaexposed to the abrasive element for treatment.

In FIG. 43, straight wire or needle 4 is driven through curved needle 16disposed in working channel 50 of double barrel epidural needle. Thisstraight wire or needle 4 is advanced until it has penetrated throughthe skin and out of the patient's body. The straight wire preferably hasa sharp tip. In FIG. 44, curved needle 16 is withdrawn from workingchannel 50, leaving straight wire or needle 4 in place. Then, as seen inFIG. 45, the epidural needle and working channel may be withdrawn fromthe patient, or, in an alternative embodiment, when using a detachableworking channel 50, the working channel alone may be withdrawn from thepatient, leaving straight wire 4 in place. In FIG. 46, straight wire 4is hooked to abrasion device 14 and/or the abrasion device's protectivesleeve 6. In FIG. 47, the abrasion device 14 and/or the device'sprotective sleeve are pulled into position by wire 4 as the wire isremoved. In FIG. 48, wire 4 has been completely removed, and theabrasion device 14 and its protective sleeve 6 are property positionedfor tissue resection, anterior to the facet 12 and ligamentum flavum 10.

In an open surgical variation, the abrasive element 14 and its cover 6may be placed through the surgical incision, from a interlaminar,translaminar, or neuroforaminal approach. Visualization and placementmay be aided via partial or complete laminectomy, facetectomy, orligamentectomy. Methods for threading the neural foramina include, butare not limited to the use of a wire, blunt needle, probe, endoscope, orsuture. After spinal neuroforaminal placement, the abrasion device 14 isused to selectively remove tissues that impinge on the neurovascularstructures within the lateral recess 108 and neural foramen 110, on theanterior side of the facet joint 12. In an open approach, as with apercutaneous approach, the device may be inserted through a needle,optionally under image guidance or with the aid of an epiduralendoscope. Once placed through the neural foramina 110 of the spine,around the anterior border of the facet joint 12, and anterior to theligamentum flavum 10, the medical practitioner may enlarge the lateralrecess and neural foramina via frictional abrasion, i.e., by sliding theabrasive surface across the tissue to be resected (e.g., far lateralligamentum flavum, anterior and medial facet, osteophytes). The abrasiondevice alternatively or additionally may be placed through the neuralforamen 110 anterior to the facet joint 12, but through or posterior tothe ligamentum flavum 10. The medical practitioner controls the forceand speed of the abrasive surface against the tissue to be removed,while optional protective covers, tubes or sleeves 6 help limit the areaexposed to the abrasive element for treatment.

Referring now to FIGS. 45-48, an additional method and apparatus forplacement of a tissue abrasion apparatus for selective surgical removalor remodeling of tissue is described. The double lumen epidural needleapparatus 84 is positioned for advancement into the epidural space 42.The covered and blunt tip of the epidural needle 2, double lumenepidural needle 84, or the blunt end of the epidural endoscope 38, maybe advanced into the ipsilateral or contralateral lateral recess 108,towards the neural foramen 110, in a direction parallel to both theadjacent ligamentum flavum 10 and the dura 46. A fiberoptic element 38has been placed within epidural needle 2, providing both a means forfiberoptic visualization of the epidural space 42 and a means to bluntthe needle and thereby protect the tip of the needle from damaging thedura 46 or neural or vascular structures. The endoscope has beenadvanced along ligamentum flavum 10 (visually a “yellow ligament”) tothe lateral recess 108. “Safe zone” 44 designates the area in which amedical practitioner may resect, ablate, or otherwise modify tissuesafely, directly visualizing the area of tissue modification through thefiberoptic element. The second lumen 50 of the two lumen needle 84 orendoscope may be used as a working channel, or to dispense the abrasiveelement 14 and/or its protective sleeve 6 (FIGS. 43-48), or the workingbarrier 134 described in the primary patent referenced herein. After theneural foramen 110 has been cannulated with a non-sharp curved needle 22or catheter (FIG. 43), and after the flexible, sharp, straight needle orwire 2 has been passed through the curved needle 22 until its tip isadvanced through the skin in the patient's back (FIG. 43), the abrasionapparatus 14 and/or its sleeve or cover 36 are pulled through the neuralforamen 110, as illustrated in FIGS. 45-48. The curved needle 22 or tubemay, for example, be fabricated from spring steel, Nitinol, or othermemory material that will allow it to be inserted through a straightneedle, but to return to a fixed curve upon exiting the straightepidural needle 2 or working channel 50. The curved needle 16 optionallymay be steerable. Preferably, the curved needle tip is not sharp, but isrounded or designed in other fashions less likely to cut tissue, inorder to reduce a risk of neural or vascular damage.

The present invention also describes methods and apparatus that may beused as a compression dressing, after tissue resection or ablation. Onevariation of the compression dressing is placed in a position where itis firmly wrapped around the facet and ligamentum flavum through theneural foramina, as illustrated in FIG. 49. By tightly pressing againsttreated tissue surfaces, such a device serves to promote desired tissueremodeling; to prevent edema from leading to impingement on neural orvascular tissue during early healing, to contain debris; to promotepostoperative hemostasis; to block scar formation between the raw tissuesurfaces and the adjacent neural and vascular structures; to avoidinflammation or irritation to neural and vascular structures fromcontact with adjacent resected tissue surfaces; and as a mechanism forsustained drug delivery post-operatively (e.g. steroids, procoagulants,adhesion barriers).

Referring now to FIGS. 49-63, a variation of the method and apparatus ofFIGS. 43-48 is described, comprising another preferred approach forplacement of the abrasion device. This series begins with FIG. 49, inwhich a double lumen, blunt tipped, epidural device 84, has already beenadvanced to the lateral recess 108. Next, FIG. 50 shows a curvedflexible needle 16, preferably with an atraumatic tip, that has beenadvanced, via the working channel 50, through the neural foramina 110.FIG. 51 illustrates threading of the straight, flexible, sharp tippedwire 4 a through the curved needle 22, and advanced posteriorly until itexits the skin of the back. In FIG. 52, the curved needle has beenwithdrawn, leaving the straight wire 4 a in place. In FIG. 53, thedouble lumen epidural apparatus 84 is slightly withdrawn, from thepatient, so that the working channel 50 is directed towards the medialside of the face complex. FIG. 54 shows the curved needle 16 advancedthrough the working channel again, adjacent to the first wire 4 a, thistime advancing the same or a different curved, flexible needle 16,towards the opposite side of the facet complex 12. FIG. 55 shows where asecond straight flexible wire 4 b is advanced through the secondplacement of a curved needle 16, this time on the medial side of thefacet joint. The second sharp, flexible, straight wire 4 b is threadedthrough this second curved needle, and subsequently, advancedposteriorly, until the sharp tip of the wire 4 b exits the skin 70. FIG.56 next shows both the curved needles and the double lumen apparatusremoved, leaving the wires 4 a and 4 b in place.

FIG. 57 shows that both wires have been attached to the two ends of theabrasive element 14 and/or the cover 6 of the abrasive element. Withaccess established, via either a percutaneous or an open approach (or acombination thereof), neural protection and/or tissue removal elementsmay be introduced via the access for safe, selective removal of tissue.It should be understood that the methods and apparatus describedhereinafter are equally applicable to both open and percutaneousapproaches. For the purpose of clarity, they may be illustratedutilizing only a percutaneous or open access, but this should in no waybe construed as limiting.

In order to reduce a risk of neurological damage during selective tissueremoval, variations of the present invention optionally may provideneural protection during tissue removal. In one variation, a neuralprotection element, such as a sheath, shield or backstop, is positionedsuch that the neural protection element separates impinging tissue inthe neural foramen from the underlying nerve root. Tissue removal thenmay proceed by advancing a tissue removal device into position betweenthe foramen and the neural protection element. When access to thestenosed region is via an open surgical procedure, it may be possiblefor the medical practitioner to manually place the neural protectionelement. Alternatively, when using either an open or a percutaneousaccess, the neural protection element may by advanced over, or pulledinto place by, an access guide wire placed as described previously.

Neural protection element 6 illustratively comprises a sheath havingopening or window that is placed across the foramen at the position ofdesired selective tissue removal. The end regions of neural protectionelement 6 disposed outside the patient optionally may be attached orclipped together to stabilize the element and free up the medicalpractitioner's hands.

As illustrated in FIGS. 57-63, a tissue removal device may be positionedbetween impinging tissue and the neural protection element for safe,selective removal of the impinging tissue. For example, tissue removaldevice 14 may be delivered through, along or in conjunction with neuralprotection element 6 to position the tissue removal device across theforamen between the impinging tissue and the neural protection elementwith tissue removal surface of device locally exposed to the impingingtissue within window of neural protection element 6. In FIG. 60, tissueremoval device 14 is coupled to access guide wire 4. In FIG. 61, thetissue removal device is pulled into position by partially or completelyremoving the guide wire. Tissue removal device 14 alternatively may bepositioned across the neural foramen in conjunction with, or at the sametime as, neural protection element 6, which optionally may be coupled toguide wire 4 and pulled into position. Furthermore, neural protectionelement 6 and tissue removal device 14 may be integrated into a singledevice. As yet another alternative, tissue removal device may beadvanced over guide wire 4.

In FIGS. 62 and 63, temporary stops 112 have been attached to neuralprotection element 6 to maintain the position of the element and free upthe medical practitioner's hands, for example, for manipulation oftissue removal device 14. The stops may hold window of sheath 6 ofelement 14 under tension against the impinging tissue. Stops 112 may beplaced or expanded, or removed or collapsed, etc., at any time asdesired; for example, the stops may be placed prior to positioning oftissue removal device 14 transforaminally. Stops 112 may comprise anyelement that temporarily maintains the position of the accesselement/guide wire, the neural protection element and/or the tissueremoval device during a selective tissue removal procedure. As mentionedpreviously, the end regions of neural protection element 6 alternativelyor additionally may be attached or clipped to one another to stabilizethe element and free up the medical practitioner's hands.

As an added safety precaution, variations of the present inventionoptionally may comprise neural localization elements to ensure properpositioning of the access element or guide wire, the neural protectionelement, and/or the tissue removal device. The neural localizationelements may comprise separate elements or may be integrated with theaccess element, the neural protection element and/or the tissue removaldevice.

Alternatively, the two wires 4 a and 4 b may be opposite ends of thesame continuous wire, with the cover 6 for the abrasive element 14already placed over the mid-portion of the wire 4. Alternatively, theabrasive element 14 may already have been placed inside said cover 6,and attached at each end to the wires 4 a and 4 b. FIGS. 58 and 59 showthe two wires 4 a and 4 b pulled and bringing the abrasive elementcover, possibly with the abrasive element 14 already placed inside saidcover 6, into position through the neural foramina. FIG. 60 illustratesthe step that follows placement of the abrasion element cover 6 atone.In FIG. 60, with the wire 4 in place inside the abrasion element cover6, the abrasive element 14 is now seen to have been attached to the endof the wire. Subsequently, the cover 6 is held open at each end by agrasping device, which also holds the cover 6 under tension against thetissue to be abraded. With the cover anchored thus, the abrasive element14 is pulled into place by the wire 4 a/b, replacing the wire, as hasoccurred for FIGS. 61 and 62. With the abrasive element in position andthe abrasive element cover 6 tightly held open and against the tissue tobe abraded, the abrasion element 14 may be pulled back and forth, undertension, against the tissue to be abraded, as in FIG. 62. Alternatively,the abrasive element may be pulled in a single direction across thetissue to be abraded. FIG. 63 illustrates the cover 6 following removalof the abrasive element. Said cover may remain in placed as acompression bandage, under tension against the freshly abraded surface,in order to promote hemostasis, promote tissue remodeling, and trapdebris post operatively.

FIG. 64 illustrates that the tissue removal apparatus can have thetissue removal device 300 and the tissue protection barrier 528. Thetissue removal device 300 can be slidably attached to an inside conduit,channel or hollow of the tissue protection barrier 528. The tissueremoval device 300 can have the working surface 538. The working surface538 can be configured to damage, and/or destroy, and/or remove theimpinging tissue. Part or all of the working surface 538 can be exposedthrough the window 536. The window 536 can be on the front side of thetissue protection barrier 528. The tissue barrier protection 528 canhave and/or elute a lubricious coating or material, for example on thesurface of the inside conduit, channel or hollow. The tissue removaldevice 300 can have and/or elute a lubricious coating or material on theentire surface and/or on the surface other than on the working surface538.

FIG. 65 illustrates that a method of using the tissue removal apparatus538 can include deploying the window adjacent to the impinging tissue424. A tension, as shown by arrows 518, can be applied to the tissueprotection barrier 528. The tissue removal device 300 can bereciprocated or oscillated, as shown by arrows 476. The oscillation can,for example, result in the working surface 538 to separate impingingtissue 424. The separated impinging tissue 424 can be removed, forexample by suction, through the tissue protection barrier 528 and/or thetissue removal device 300. Section D can be equivalent to sections A, B,or C.

The working surface 538 can have one or more non-powered mechanicaltissue removal elements. The non-powered mechanical tissue removalelements can be abrasives such as abrasive belts or ribbons, cuttingelements such as blades, knives, scissors or saws, rongeurs, grinders,files, debriders, scrapers, graters, forks, picks, burrs, rasps,shavers, or combinations thereof.

The mechanical tissue removal elements can be used in combination or notin combination with the energy delivery device. The mechanical tissueremoval elements can be pushed into and/or drawn across the impingingtissue 424 to remove the tissue by cutting, shaving, slicing,scissoring, guillotining, scraping, tearing, abrading, debriding,poking, mutilating, or combinations thereof. The mechanical tissueremoval elements (e.g., blades) can be drawn across the impinging tissue424 in a single direction and/or can be reciprocated. The mechanicaltissue removal elements can be manually controlled and/orelectronically, pneumatically or hydraulically powered. The mechanicaltissue removal elements can be embedded with abrasives and/or haveabrasive coatings, such as a diamond or oxide coating.

The blades can have various shapes, sizes and configurations. The bladescan coact, for example, in a guillotine-type or scissor-type cuttingaction. The blades can be attached to or integral with the tissueremoval device. The blades can be formed by grinding, punching orstamping through the tissue removal device. The blades can be formed bygrinding of a punched or stamped edge of the tissue removal device. Theblades can be formed by a chemical etching process. The blades can havea 3-dimensional profile to facilitate cutting, for example, a bow or acorrugation or a ‘cheese grater’ profile. The blades can be placed atone or more angles relative to the direction of tissue removal. Theblades can be configured with the blade cutting across the tissue (i.e.,similar to a band saw). The blades can have cutting surfaces. Thecutting surfaces can be oriented in a single or multiple directions. Theblades can be serrated.

The saw can be a wire saw or saws. The wire saw can be a Gigli saw.Multiple wire saws or Gigli saws can be joined or woven together orflattened to form a substantially planar cutting surface. The wire sawcan be mounted on a flat ribbon. The ribbon can be a depth stop, forexample, limiting for saw penetration.

The tissue removal device 300 can have one or more powered mechanicaltissue removal elements. The powered mechanical tissue removal elementscan have, for example, band saws, belt shavers, rotary burrs or blades,reciprocating burrs or blades, or combinations thereof.

Devices and elements known to those having ordinary skill in the art canbe used to remove debris from, and/or irrigate, and/or provide suctionto, the epidural space 42 including the lateral recess 108 and neuralforamen 110 and/or to the tissue removal device itself. The devices andelements for removing debris can be integral with the needle 464 and/orthe catheter 24. Debris removal, and/or suction and/or irrigation may beprovided intermittently or continuously, as desired by the medicalpractitioner. Debris removal can include suction and/or irrigation. Thetissue removal device 300 can capture debris. Irrigation and/or suctionin the tissue removal device 300 can remove the debris from the tissueremoval device 300, for example by the debris exiting along the needle464 and/or catheter 24.

Turning now to FIG. 66A-66I, more detailed figures of one embodiment oftissue modification device 102 are shown. Referring to FIG. 66A, tissuemodification device 102 may include elongate body 108 having proximalportion 107 and distal portion 109, a window 111 disposed along elongatebody 108, two tissue modifying blades 110 exposed through window 111,and handle 104 with actuator 106 coupled with proximal portion 107. Inthe embodiment shown, the tissue modifying members comprise blades 110,although in alternative embodiments other tissue modifying members maybe added or substituted.

In various embodiments, elongate body 108 may have any number ofdimensions, shapes, profiles and amounts of flexibility. For example,distal portion 109 is shown having a curved shape to demonstrate that atleast a portion of elongate body 108 may be flexible. In variousembodiments, elongate body 108 may have one or more of a round, ovoid,ellipsoid, flat, cambered flat, rectangular, square, triangular,symmetric or asymmetric cross-sectional shape. As shown in FIGS. 66C and66D, in the pictured embodiment, elongate body 108 has a relatively flatconfiguration, which may facilitate placement of body 108 between targetand non-target tissues. Distal portion 109 of body 108 may be tapered,to facilitate its passage into or through narrow spaces as well asthrough small incisions on a patient's skin. Body 108 may also include aslightly widened portion around the area of window 111 and blades. Inone embodiment, such as an embodiment used for modifying tissue in aspine, body 108 may have a small profile, such as having a height of notmore than 10 mm at any point along its length and a width of not morethan 20 mm at any point along its length, or more preferably a heightnot more than 5 mm at any point along its length and a width of not morethan 10 mm at any point along its length, or even more preferably aheight not more than 2 mm at any point along its length and a width ofnot more than 4 mm at any point along its length. Body 108 may be longenough to extend through a first incision on a patient, between targetand non-target tissue, and out a second incision on a patient.Alternatively, body 108 may be long enough to extend through a firstincision, between the target and non-target tissue, and to an anchoringlocation within the patient. In another alternative embodiment, body 108may be long enough to extend through a first incision, between thetarget and non-target tissue, to a location nearby but distal to thetarget tissue within the patient, with some portion of tissuemodification device 102 anchored to guide member 116. In someembodiments, elongate body 108 includes at least one feature forallowing passage of the body over a guidewire or other guide member orto allow passage of one or more guide members over or through body 108.For example, in various embodiments body 108 may include one or moreguidewire lumens, rails, tracks, lengthwise impressions or somecombination thereof.

In one embodiment, elongate body 108 is predominantly flexible along itslength and comprises any suitable flexible material, such as thin,flexible metals, plastics, fabrics or the like. In some embodiments, itmay be advantageous to include one or more rigid sections in elongatebody 108, such as to impart pushability to a portion of body 108 or tofacilitate application of force to tissue modification members 110without causing unwanted bending or kinking of elongate body 108. Insuch embodiments, rigidity may be conferred by using additionalmaterials in body 108 or by making the rigid portions thicker or wideror of a different shape.

Handle 104 may have any suitable configuration according to variousembodiments. Similarly, actuator 106 may include any of a number ofactuation devices in various embodiments. In the embodiment shown inFIG. 66A, actuator 106 comprises a trigger or moving handle portion,which is grasped by a user and pulled or squeezed toward handle 104 tobring blades 110 together to cut tissue. In an alternative embodiment,actuator 106 instead may include a switch or button for activating aradiofrequency surgical ablation tissue modifying member. In yet anotherembodiment, actuator 106 may include a combination trigger and switch,one or more pull wires, any suitable form of lever and/or somecombination thereof.

FIGS. 66B-66D show in greater detail a portion of tissue modificationdevice 102. In these figures, window 111 and blades 110 are more clearlyseen. In one embodiment, at least a portion of elongate body 108 andblades 110 may have a slightly curved configuration. In alternativeembodiments, at least a portion of elongate body 108 and blades 110 maybe flat. In other alternative embodiments, tissue modification memberssuch as blades 110 may be proud to elongate body 108.

Blades 110 include a distal 110 a and a proximal blade 110 b that resideat the distal and proximal edges, respectively, of window 111 ofelongate body 108. Window 111 of body 108 may accommodate both soft andhard tissue when the device is forcibly applied to the surface of atarget tissue site. The top view of the distal portion of elongate body108, shown in FIG. 66C, depicts the angled edges of distal blade 110 aand proximal blade 110 b, which facilitate shearing of target tissue. Inalternative embodiments, blades 110 may have any of a number ofalternative shapes and configurations. The distal portion of body 108may have a very low profile (height compared to width), as shown in sideview FIG. 66D, where only blades 110 protrude from the top surface ofthe elongate body 108. In one embodiment, also as shown in FIG. 66D, aguidewire tube 120 (or lumen) may extend from (or be coupled with) alower surface of elongate body 108. The lower surface of elongate body108 is an example of a protective or non-tissue-modifying surface.

In one embodiment, distal blade 110 a is coupled with two pull-wires118, as seen in FIGS. 66C, 66E and 66F. Pull-wires 118 coupled to andtranslated by actuator 106 on handle 104 may be used to drive distalblade 110 a proximally to contact the cutting edge of proximal blade 110b, thus cutting tissue. Other alternative mechanisms for driving blades110, such as gears, ribbons or belts, magnets, electrically powered,shape memory alloy, electro magnetic solenoids and/or the like, coupledto suitable actuators, may be used in alternative embodiments. Asmentioned, in one embodiment distal blade 110 a and/or proximal blade110 b may have an outwardly curvilinear shape along its cutting edge.Alternatively, distal blade 110 a may have a different blade shape,including flat, rectilinear, v-shaped, and inwardly curvilinear (concavevs. convex). The cutting edge of either blade 110 may have a sharp edgeformed by a simple bevel or chamfer. Alternatively or in addition, acutting edge may have tooth-like elements that interlock with a cuttingedge of an opposing blade, or may have corrugated ridges, serrations,rasp-like features, or the like. In various embodiments, both blades 110may be of equal sharpness, or alternatively one blade 110 may be sharpand the other substantially flat to provide a surface against which thesharp blade 110 may cut. Alternately or in addition, both cutting edgesmay be equally hard, or a first cutting edge may be harder than asecond, the latter of which deflects under force from the first harderedge to facilitate shearing of the target tissue.

FIGS. 66E and 66F show cross-sectional views through elongate body atlines A-A and B-B, respectively, of FIG. 66C. In some embodiments, allor a portion of elongate body 108, such as the lower surface shown inFIG. 66E, may include a lubricious surface for facilitating manipulationof the tool in the surgical space and at the anatomical site. Thelubricious lower surface also provides a barrier between blades 110 andnon-target tissue in the surgical space. The lower surface may include aguide member lumen 120 to accommodate a guidewire or other access deviceor rail. FIG. 66E shows distal blade 110 coupled with pull wires 118.FIG. 66F shows proximal blade 110 b, which is not coupled with pullwires 118 but rather fixed to body 108. In various alternativeembodiments, proximal blade 110 b may be movable distally while distalblade 110 a is static, both blades may be moved toward one another, or adifferent number of blades may be used, such as one blade drawn toward abackstop or more than two blades, one or more of which may be mobile. Invarious alternative embodiments, guide member lumen 120 may beaccommodated on a side surface or more centrally within elongate body108. In further alternative embodiments, the one or more guide memberlumens 120 may comprise one or more various cross sectional shapes, forexample substantially round, substantially oval, or substantiallyrectabular, to accommodate alternative guide members, for example flator rectangular guidewires, needles or rails. In still other alternativeembodiments guide member lumen 120 may be adjustably coupled with theelongate body 108 to enable manipulation of the location of the elongatebody 108 and therefore the tissue modifying members 110 relative to theguiding member.

Referring now to FIGS. 66G-66I, blades 110 are shown in their closedposition. In one embodiment, when distal blade 110 a is drawn proximallyto cut tissue, at least some of the cut tissue is captured in a hollowinterior portion of elongate body 108. Various embodiments may furtherinclude a cover, a cut tissue housing portion and/or the like forcollecting cut tissue and/or other tissue debris. Such collected tissueand debris may then be removed from the patient during or after a tissuemodification procedure. During a given tissue modification procedure,distal blade 110 a may be drawn proximally to cut tissue, allowed toretract distally, and drawn proximally again to further cut tissue asmany times as desired to achieve a desired amount of tissue cutting.

Blades 110 may be made from any suitable metal, polymer, ceramic, orcombination thereof. Suitable metals, for example, may include but arenot limited to stainless steel (303, 304, 316, 316L), nickel-titaniumalloy, tungsten carbide alloy, or cobalt-chromium alloy, for example,Elgiloy® (Elgin Specialty Metals, Elgin, USA), Conichrome® (CarpenterTechnology, Reading, Pa., USA), or Phynox® (Imphy SA, Paris, France). Insome embodiments, materials for the blades or for portions or coatingsof the blades may be chosen for their electrically conductive orthermally resistive properties. Suitable polymers include but are notlimited to nylon, polyester, Dacron®, polyethylene, acetal, Delrin®(DuPont, Wilmington, Del.), polycarbonate, nylon, polyetheretherketone(PEEK), and polyetherketoneketone (PEKK). In some embodiments, polymersmay be glass-filled to add strength and stiffness. Ceramics may includebut are not limited to aluminas, zirconias, and carbides. In variousembodiments, blades 110 may be manufactured using metal injectionmolding (MIM), CNC machining, injection molding, grinding and/or thelike. Pull wires 118 be made from metal or polymer and may havecircular, oval, rectangular, square or braided cross-sections. In someembodiments, a diameter of a pull wire 118 may range from about0.001″-0.050″, and more preferably from about 0.010″-0.020″.

Depending on the tissue to be treated or modified, activating blades 110(or other tissue modifying members in alternative embodiments) may causethem to modify target tissue along an area having any of a number ofsuitable lengths. In use, it may also be advantageous to limit theextent of action of blades 110 or other tissue modifying members to adesired length of tissue, thus not allowing blades 110 to affect tissuebeyond that length. In so limiting the effect of blades, unwantedmodification of or damage to, surrounding tissues and structures may belimited or even eliminated. In one embodiment, for example, where thetissue modification device is used to modify tissue in a spine, blades110 may operate along a length of target tissue of no more than 10 cm,and preferably no more than 6 cm, and even more preferably no more than3 cm. Of course, in other parts of the body and to address othertissues, different tissue modification devices may be used and tissuemodifying members may have many different lengths of activity. In oneembodiment, to facilitate proper location of tissue modifying members,such as blades 110, relative to target tissue, the tissue modifyingmembers and/or the elongate body and/or one or more additional featuresintended for just such a purpose may be composed of a material readilyidentifiable via x-ray, fluoroscopic, magnetic resonance or ultrasoundimaging techniques.

In various embodiments, a number of different techniques may be used toprevent blades 110 (or other tissue modifying members) from extendingsignificantly beyond the target tissue. In one embodiment, for example,preventing blades 110 from extending significantly beyond the targettissue involves holding tissue modification device 102 as a wholepredominantly stable to prevent device 102 from translating in adirection toward its proximal portion or toward its distal portion whileactivating blades 110. Holding device 102 stable is achieved byanchoring one end of the device and applying tensioning force at or nearthe other end, as described further below.

In the embodiment shown in FIGS. 66A-66I, pull wires 118 are retractedproximally by squeezing actuator 106 proximally. In an alternativeembodiment, squeezing actuator 106 may cause both blades 110 totranslate inward so that they meet approximately in the middle of window111. In a further embodiment, distal blade 110 a may be returned to it'sstarting position by a pulling force generated from the distal end ofdevice 102, for example by using a distal actuator that is attached todistal wires, or by pulling on the distal guide member which is attachedto distal blade 110 a. In yet another alternative embodiment, proximalblade 110 b may be moved to cut by a pulling force generated from thedistal end of device 102, for example by using a distal actuator that isattached to distal wires, or by pulling on the distal guide member whichis attached to proximal blade 110 b. In yet another embodiment,squeezing actuator 106 my cause proximal blade 110 b to move distallywhile distal blade 110 a stays fixed. In other alternative embodiments,one or more blades 110 may move side-to-side, one or more blades 110 maypop, slide or bow up out of window 111 when activated, or one or moreblades 110 may expand through window. In another embodiment, one or moreblades 110 and/or other tissue modifying members of device 102 may bepowered devices configured to cut, shave, grind, abrade and/or resecttarget tissue. In other embodiments, one or more blades may be coupledwith an energy transmission device, such as a radiofrequency (RF) orthermal resistive device, to provide energy to blade(s) 110 for cutting,ablating, shrinking, dissecting, coagulating or heating and thusenhancing tissue modification. In another embodiment, a rasp or file maybe used in conjunction with or coupled with one or more blades. In anyof these embodiments, use of actuator 106 and one or more moving blades110 provides for tissue modification with relatively little overalltranslation or other movement of tissue modification device 102. Thus,target tissue may be modified without extending blades 110 or othertissue modification members significantly beyond an area of targettissue to be treated.

Referring now to FIGS. 67A-67C, in an alternative embodiment, a tissuemodification device 202 may include an elongate body 208 having aproximal portion and a distal portion 209, a handle 204 and actuator 206coupled with proximal portion, and a window 211 and tissue modifyingmember 210 disposed near distal portion 209. As seen more clearly inFIGS. 4B and 4C, in the embodiment shown, tissue modifying member 210comprises an RF electrode wire loop. Wire loop 210 may comprise anysuitable RF electrode, such as those commonly used and known in theelectrosurgical arts, and may be powered by an internal or external RFgenerator, such as the RF generators provided by Gyrus Medical, Inc.(Maple Grove, Minn.). Any of a number of different ranges of radiofrequency may be used, according to various embodiments. For example,some embodiments may use RF energy in a range of between about 70 hertzand about 5 megahertz. In some embodiments, the power range for RFenergy may be between about 0.5 Watts and about 200 Watts. Additionally,in various embodiments, RF current may be delivered directly intoconductive tissue or may be delivered to a conductive medium, such assaline or Lactate Ringers solution, which may in some embodiments beheated or vaporized or converted to plasma that in turn modifies targettissue. Distal portion 209 includes a tapered tip, similar to thatdescribed above, to facilitate passage of elongate body 208 into narrowanatomical sites. Handle 204 and actuator 206 are similar to thosedescribed above, although in the embodiment of FIGS. 67A-67C, actuator206 may be used to change the diameter of the wire loop 210. Usingactuator 206, wire loop 210 may be caused to extend out of window 211,expand, retract, translate and/or the like. Some embodiments mayoptionally include a second actuator (not shown), such as a foot switchfor activating an RF generator to delivery RF current to an electrode.

Elongate body 208 may be fabricated from any suitable material and haveany of a number of configurations. In one embodiment, body 208 comprisesa metal tube with a full-thickness slit (to unfold the tube into a flatform—not shown) or stiffening element (not shown). The split tubeprovides for a simple manufacturing process as well as a conductivepathway for bi-polar RF operation.

Referring to FIG. 67C, insulators 222 may be disposed around a portionof wire loop 210 so that only a desired portion of wire loop 210 maytransfer RF current into the tissue for tissue modifying capability.Wire loop 210, covered with insulators 222 may extend proximally intosupport tubes 218. In various alternative embodiments, an electrodetissue modifying member (of which wire loop 210 is but one example) maybe bipolar or monopolar. For example, as shown in FIG. 67C, a sleeve 224housed toward the distal portion of window 211 may act as a returnelectrode for wire loop 210 in a bipolar device. Wire loop electrodes210 may be made from various conductive metals such as stainless steelalloys, nickel titanium alloys, titanium alloys, tungsten alloys and thelike. Insulators 222 may be made from a thermally and electricallystable polymer, such as polyimide, polyetheretherketone (PEEK),polytetrafluoroethylene (PTFE), polyamide-imide, or the like, and mayoptionally be fiber reinforced or contain a braid for additionalstiffness and strength. In alternative embodiments, insulators 222 maybe composed of a ceramic-based material.

In one embodiment, wire loop 210 may be housed within elongate body 208during delivery of tissue modification device 202 into a patient, andthen caused to extend up out of window 211, relative to the rest of body208, to remove tissue. Wire loop 210 may also be flexible so that it maypop or bow up out of window 211 and may deflect when it encounters hardtissue surfaces. Wire loop 210 may have any of a number of shapes, suchas curved, flat, spiral or ridged. Wire loop 210 may have a diametersimilar to the width of body 208, while in alternative embodiments itmay expand when extended out of window 211 to have a smaller or largerdiameter than that of body 208. Pull wires (not shown) may be retractedproximally, in a manner similar to that described above, in order tocollapse wire loop 210, decrease the diameter and lower the profile ofthe wire loop 210, and/or pull wire loop 210 proximally to remove tissueor be housed within body 208. The low profile of the collapsed wire loop210, facilitates insertion and removal of tissue modification device 202prior to and after tissue modification. As the wire loop 210 diameter isreduced, support tubes 218 deflect toward the center of elongate body208.

In an alternative embodiment (not shown), tissue modification device 202may include multiple RE wire loops 210 or other RE members. In anotherembodiment, device 202 may include one or more blades as well as RE wireloop 210. In such an embodiment, wire loop 210 may be used to remove orotherwise modify soft tissues, such as ligamentum flavum, or to providehemostasis, and blades may be used to modify hard tissues, such as bone.In other embodiments, as described further below, two separate tissuemodification devices (or more than two devices) may be used in oneprocedure to modify different types of tissue, enhance modification ofone type of tissue or the like.

In other alternative embodiments, tissue modification devices 202 mayinclude tissue modifying members such as a rongeur, a curette, ascalpel, a scissors, a forceps, a probe, a rasp, a file, an abrasiveelement, one or more small planes, a rotary powered mechanical shaver, areciprocating powered mechanical shaver, a powered mechanical burr, alaser, an ultrasound crystal a cryogenic probe, a pressurized water jet,a drug dispensing element, a needle, a needle electrode, or somecombination thereof. In some embodiments, for example, it may beadvantageous to have one or more tissue modifying members that stabilizetarget tissue, such as by grasping the tissue or using tissue restraintssuch as barbs, hooks, compressive members or the like. In oneembodiment, soft tissue may be stabilized by applying a contained,low-temperature substance (for example, in the cryo-range oftemperatures) that hardens the tissue, thus facilitating resection ofthe tissue by a blade, rasp or other device. In another embodiment, oneor more stiffening substances or members may be applied to tissue, suchas bioabsorbable rods.

Referring now to FIGS. 68A-68D, one embodiment of a method for modifyingtissue in a spine is demonstrated in simplified, diagrammatic,cross-sectional views of a portion of a patient's back and spine. FIG.68A shows a portion of the patient's back in cross section, with aportion of a vertebra, the spinal cord with branching nerve roots, andtarget tissue, which in this illustration is the ligamentum flavum andpossibly a portion of the facet capsule. The target tissue is typicallyimpinging directly on one or more of the group including nerve roots,neurovascular structures, dorsal root ganglia, cauda equina, orindividual nerves.

In FIG. 68B, tissue modification device 102 has been positioned in thepatient's back to perform a tissue modification procedure. Variousmethods, devices and systems for introducing device 102 into the patientand advancing it to the position for modifying tissue are described infurther detail below. Generally, device 102 my be positioned via apercutaneous or open surgical procedure, according to variousembodiments. In one embodiment, device 102 may be inserted into thepatient through a first incision 240, advanced into the spine andbetween target tissue and non-target tissue (such as spinal cord, nerveroots, nerves and/or neurovascular tissue), and further advanced so adistal portion of elongate body 108 exits a second (or distal) incision242 to reside outside the patient. In positioning device 102, one ormore tissue modifying members (not shown) are positioned to face thetarget tissue, while one or more protective portions of elongate body108 face non-target tissue.

Referring to FIG. 68C, once device 102 is positioned in a desiredlocation, anchoring force may be applied at or near the distal portionof elongate body 108. In one embodiment, applying anchoring forceinvolves a user 244 grasping body 108 at or near its distal portion. Inalternative embodiments, as described further below, anchoring force maybe applied by deploying one or more anchor members disposed at or nearthe distal portion of body 108, or by grasping a guidewire or otherguide member extending through at least part of body 108. Once theanchoring force is applied, proximally-directed tensioning force may beapplied to device 102, such as by pulling proximally on handle 104(one-directional, diagonal arrows). This tensioning force, when appliedto the substantially anchored device 102, may help urge the tissuemodifying member(s) against the target tissue (one-directional, verticalarrows near target tissue), thus enhancing contact with the targettissue and facilitating its modification. With the tissue modifyingmember(s) contacting the target tissue, actuator 106 may be squeezed orpulled (two-headed arrow) to cause the tissue modifying member(s) tomodify tissue, (Alternative actuators may be activated in different waysin alternative embodiments.)

In various alternative embodiments, certain of the above-described stepsmay be carried out in different order. For example, in one embodimentthe distal portion of elongate body 108 may be anchored within oroutside the patient before the tissue modifying members are positionedadjacent the target tissue. In another alternative embodiment, theproximal portion of device 102 may be anchored, and the tensioning forcemay be applied to the distal portion of device 102. In yet anotherembodiment, tensioning force may be applied to both ends of the device.In yet another embodiment, a second handle and actuator may be coupledwith the distal end of body 108 after it exits the patient's back,allowing tensioning forces as well as tissue modifying actuation tooccur at both the proximal and distal portions of device 102. Byanchoring one end of device 102 and applying tensioning force to theopposite end, contact of the tissue modifying members with the targettissue is enhanced, thus reducing or eliminating the need fortranslating or otherwise moving device 102 as a whole and reducing theoverall profile and the resulting access pathway required to positionthe device. Reducing movement and profile of device 102 and using tissuemodifying members confined to a relatively small area of device 102helps facilitate target tissue modification while minimizing oreliminating damage to surrounding tissues or structures.

As mentioned above, tissue may be modified using one tissue modificationdevice or multiple devices, according to various embodiments. In oneembodiment, for example, an RF electrosurgical tissue modificationdevice may be used in the patient to remove soft tissue such asligament, and a bladed tissue modification device such as a rongeur maythen be used to remove additional soft tissue, calcified soft tissue, orhard tissue such as bone. In some embodiments, such multiple devices maybe inserted, used and removed serially, while in alternative embodimentssuch devices may be inserted into the patient at the same time to beused in combination.

Referring to FIG. 68D, using one or more tissue modification devices102, a desired amount of target tissue may be removed from more than onearea in the spine. FIGS. 68A-68C demonstrate removal of target tissue onone side of the spine, and that method or a similar method may also beused to remove target tissue on an opposite side of the spine, as shownin FIG. 68D, where target tissue has been removed from both sides. Thatthe desired amount of tissue has been removed may be confirmed bytactile feedback from the device or from a separate device, by testingnerve conduction through one or more previously impinged nerves, bytesting blood flow through one or more previously impinged bloodvessels, by passing (independently or over the guide member) ameasurement probe or sound through the treated portion, through one ormore radiographic tests, through some combination thereof, or by anyother reasonable means.

Referring now to FIG. 69A, tissue modification device 102 is shown withone embodiment of a distal anchoring member 250 deployed at thepatient's skin. In various embodiments, anchoring members may includebut are not limited to one or more handles, barbs, hooks, screws, togglebolts, needles, inflatable balloons, meshes, stents, wires, lassos,backstops or the like. In some embodiments, anchoring members 250 may bedisposed at the extreme distal portion 109 of elongate body 108, whilein other embodiments anchoring members 250 may be located moreproximally. In the embodiment shown, anchoring members 250 are deployedat the patient's skin. In an alternative embodiment, anchoring may beachieved outside the patient by deploying one or more anchoring members250 above the skin and having a user grasp the anchoring members 250. Inan alternative embodiment, anchoring may be achieved outside the patientby deploying one or more anchoring members 250 above the skin and havinga user grasp anchoring members 250, after tissue modification device 102has been anchored to the guide member. In another alternativeembodiment, anchoring may be achieved outside the patient by attachinganchoring member 250 to an external device, for example one that ismounted on the patient or on the procedure table. In a furtheralternative embodiment, anchoring may be achieved outside the patient byattaching the guide member to an external device, for example one thatis mounted to on the patient or on the procedure table, after tissuemodification device 102 has been anchored to the guide member. Anchoringmembers 250 generally are deployable from a first, contractedconfiguration to facilitate delivery of device 102, to a second,expanded configuration to facilitate anchoring. This change inconfiguration may be achieved, for example, by using shape memory orsuper-elastic materials, by spring loading anchoring members 250 intobody 108 or the like. In most embodiments, anchoring members 250 mayalso be collapsed down into the first, contracted configuration after atissue modification procedure has been performed, to facilitatewithdrawal of device 102 from the patient. In an alternative embodiment,anchoring members 250 may detach from body 108 and may be easilyremovable from the patient's skin.

FIG. 69B shows tissue modification device 102 with an alternativeembodiment of a distal anchoring member 260. Here, distal anchoringmember 260 includes multiple hooks or barbs extended out the distalportion 109 of elongate body 108 within the patient's back. In usingsuch an embodiment, it may not be necessary to pass guide member 117through a second, distal incision on the patient, although in someembodiments guide member 117 may extend significantly beyond distalportion 109. Anchoring member(s) 260, according to various embodiments,may be deployed so as to anchor to bone, ligament, tendon, capsule,cartilage, muscle, or any other suitable tissue of the patient. They maybe deployed into vertebral bone or other suitable tissue immediatelyadjacent an intervertebral foramen or at a location more distant fromthe intervertebral foramen. When a tissue modification procedure iscomplete, anchoring members 260 are retracted within elongate body forremoval of device 102 from the patient.

Although various illustrative embodiments are described above, any of anumber of changes may be made to various embodiments without departingfrom the scope of the invention as described by the claims. For example,the order in which various described method steps are performed mayoften be changed in alternative embodiments, and in other alternativeembodiments one or more method steps may be skipped altogether. Optionalfeatures of various device and system embodiments may be included insome embodiments and not in others. Therefore, the foregoing descriptionis provided primarily for exemplary purposes and should not beinterpreted to limit the scope of the invention as it is set forth inthe claims.

1. A method of cutting a ligament of a patient, the method comprising:advancing a cannulated probe into a patient; advancing a tissuemodification device assembly through the cannulated probe and anteriorto a ligament of a patient; advancing the distal end of the tissuemodification device assembly posteriorly through the skin of the patientsuch that it exits the patient; exposing at least one tissuemodification element of the tissue modification device assembly; andreciprocating at least a portion of the tissue modification deviceassembly by alternately pulling on proximal and distal portions of thetissue modification device assembly to draw the at least one tissuemodification element across the ligament to cut the ligament.
 2. Themethod of claim 1, further comprising the step of confirming properplacement with a nerve stimulator.
 3. The method of claim 2, furthercomprising the step of attaching a nerve stimulator to a tissuemodification device assembly.
 4. The method of claim 1, furthercomprising the step of coupling a distal handle to the distal end of thetissue modification device assembly, exterior to the patient.
 5. Amethod of cutting a ligament of a patient, the method comprising:advancing a tissue modification device assembly into a patient andanterior to a ligament of a patient; advancing the distal end of thetissue modification device assembly posteriorly through the skin of thepatient such that it exits the patient; exposing at least one tissuemodification element of the tissue modification device assembly; andreciprocating at least a portion of the tissue modification deviceassembly by alternately pulling on proximal and distal portions of thetissue modification device assembly to draw the at least one tissuemodification element across the ligament to cut the ligament.
 6. Themethod of claim 5, further comprising the step of confirming properplacement with a nerve stimulator.
 7. The method of claim 6, furthercomprising the step of attaching a nerve stimulator to a tissuemodification device assembly.
 8. The method of claim 5, furthercomprising the step of coupling a distal handle to the distal end of thetissue modification device assembly, exterior to the patient.
 9. Asystem for cutting a ligament of a patient, the system comprising: aprobe configured to be advanced into a patient; a tissue modificationdevice, wherein tissue modification device comprises: a proximal handle,at least one tissue modification element configured cut ligament, asharp distal tip, wherein the sharp distal tip is configured to beadvanced anterior to a ligament of a patient and posteriorly through theskin of the patient such that it exits the patient; and a sheathconfigured to limit the exposure of the tissue modification element oftissue modification device, wherein the tissue modification device isconfigured for placement within the sheath such that tissue modificationelement is locally exposed by the sheath.
 10. The system of claim 9,further comprising a nerve stimulator configured to couple to the tissuemodification device to confirm correct placement of the tissuemodification device.
 11. The system of claim 9, further comprising adistal handle configured to couple to the sharp distal tip of the tissuemodification device.
 12. The system of claim 9, wherein the probe is acannulated probe and the tissue modification device is configured to bedeployed through the cannulated probe.
 13. A device for cutting ligamentof a patient, the device comprising: a proximal handle; at least onetissue modification element configured cut ligament; a sharp distal tip,wherein the sharp distal tip is configured to be advanced anterior to aligament of a patient and posteriorly through the skin of the patientsuch that it exits the patient; and a sheath configured to limit theexposure of the tissue modification element, wherein the tissuemodification element is configured for placement within the sheath suchthat tissue modification element is locally exposed by the sheath. 14.The device of claim 13, further comprising a distal handle configured tocouple to the sharp distal tip.
 15. A system for cutting a ligament of apatient, the system comprising: a probe configured to be advanced into apatient; a tissue modification device, wherein tissue modificationdevice comprises: a proximal handle, an abrasive surface configured cutligament, a sharp distal tip, wherein the sharp distal tip is configuredto be advanced anterior to a ligament of a patient and posteriorlythrough the skin of the patient such that it exits the patient; and aprotective cover disposed about the tissue modification deviceconfigured to limit the exposure of the abrasive surface.
 16. The systemof claim 15, further comprising a nerve stimulator configured to coupleto the tissue modification device to confirm correct placement of thetissue modification device.
 17. The system of claim 15, furthercomprising a distal handle configured to couple to the sharp distal tipof the tissue modification device.
 18. The system of claim 15, whereinthe probe is a cannulated probe and the tissue modification device isconfigured to be deployed through the cannulated probe.